diff --git a/Make.defs b/Make.defs
index 83094e891..3bef69a57 100644
--- a/Make.defs
+++ b/Make.defs
@@ -96,7 +96,7 @@ endef
 
 # Standard include path
 
-CFLAGS   += ${shell $(INCDIR) "$(CC)" "$(APPDIR)$(DELIM)include"}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" "$(APPDIR)$(DELIM)include"}
+CFLAGS   += ${INCDIR_PREFIX}"$(APPDIR)$(DELIM)include"
+CXXFLAGS += ${INCDIR_PREFIX}"$(APPDIR)$(DELIM)include"
 
 NUTTXLIB ?= $(call CONVERT_PATH,$(TOPDIR)$(DELIM)staging)
diff --git a/boot/mcuboot/Make.defs b/boot/mcuboot/Make.defs
index 8b4ae5ff1..f56743811 100644
--- a/boot/mcuboot/Make.defs
+++ b/boot/mcuboot/Make.defs
@@ -23,12 +23,12 @@ CONFIGURED_APPS += $(APPDIR)/boot/mcuboot
 
 # It allows import of NuttX implementation headers for MCUboot interfaces.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/boot/mcuboot/mcuboot/boot/nuttx/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/boot/mcuboot/mcuboot/boot/nuttx/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/boot/mcuboot/mcuboot/boot/nuttx/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/boot/mcuboot/mcuboot/boot/nuttx/include
 
 # It allows import of MCUboot's bootutil library headers.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/boot/mcuboot/mcuboot/boot/bootutil/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/boot/mcuboot/mcuboot/boot/bootutil/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/boot/mcuboot/mcuboot/boot/bootutil/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/boot/mcuboot/mcuboot/boot/bootutil/include
 
 endif
diff --git a/boot/mcuboot/Makefile b/boot/mcuboot/Makefile
index f60b0fc81..4b2862417 100644
--- a/boot/mcuboot/Makefile
+++ b/boot/mcuboot/Makefile
@@ -72,8 +72,8 @@ CSRCS += $(MCUBOOT_UNPACK)/ext/tinycrypt/lib/source/aes_encrypt.c \
          $(MCUBOOT_UNPACK)/ext/tinycrypt/lib/source/sha256.c \
          $(MCUBOOT_UNPACK)/ext/tinycrypt/lib/source/utils.c
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" mcuboot/ext/tinycrypt/lib/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" mcuboot/ext/tinycrypt/lib/include}
+CFLAGS += ${INCDIR_PREFIX}mcuboot/ext/tinycrypt/lib/include
+CXXFLAGS += ${INCDIR_PREFIX}mcuboot/ext/tinycrypt/lib/include
 endif
 
 $(MCUBOOT_TARBALL):
diff --git a/canutils/candump/Makefile b/canutils/candump/Makefile
index 869cbced4..080ca6436 100644
--- a/canutils/candump/Makefile
+++ b/canutils/candump/Makefile
@@ -28,7 +28,7 @@ PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = $(CONFIG_CANUTILS_CANDUMP_STACKSIZE)
 MODULE = $(CONFIG_CANUTILS_CANDUMP)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/canutils/libcanutils}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/canutils/libcanutils
 MAINSRC = candump.c
 
 include $(APPDIR)/Application.mk
diff --git a/canutils/cansend/Makefile b/canutils/cansend/Makefile
index 0f106276d..52d17f3f8 100644
--- a/canutils/cansend/Makefile
+++ b/canutils/cansend/Makefile
@@ -28,7 +28,7 @@ PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = $(CONFIG_CANUTILS_CANSEND_STACKSIZE)
 MODULE = $(CONFIG_CANUTILS_CANSEND)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/canutils/libcanutils}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/canutils/libcanutils
 MAINSRC = cansend.c
 
 include $(APPDIR)/Application.mk
diff --git a/canutils/lely-canopen/Make.defs b/canutils/lely-canopen/Make.defs
index 05dcb5161..a762a23a7 100644
--- a/canutils/lely-canopen/Make.defs
+++ b/canutils/lely-canopen/Make.defs
@@ -23,6 +23,6 @@ CONFIGURED_APPS += $(APPDIR)/canutils/lely-canopen
 
 # It allows `<lely/xxx.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/canutils/lely-canopen/lely-core/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/canutils/lely-canopen/lely-core/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/canutils/lely-canopen/lely-core/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/canutils/lely-canopen/lely-core/include
 endif
diff --git a/canutils/lely-canopen/Makefile b/canutils/lely-canopen/Makefile
index 4c6c0c555..8bb3f04e4 100644
--- a/canutils/lely-canopen/Makefile
+++ b/canutils/lely-canopen/Makefile
@@ -151,7 +151,7 @@ endif
 
 # enable config.h
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/include/canutils/lely}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/include/canutils/lely
 CFLAGS += -DHAVE_CONFIG_H=1
 
 CFLAGS += -Wno-shadow -Wno-undef
diff --git a/canutils/libcanardv0/Makefile b/canutils/libcanardv0/Makefile
index a337fd3a7..e708e1208 100644
--- a/canutils/libcanardv0/Makefile
+++ b/canutils/libcanardv0/Makefile
@@ -33,7 +33,7 @@ LIBCANARDV0_DRVDIR = $(LIBCANARDV0_SRCDIR)$(DELIM)drivers$(DELIM)nuttx
 APPS_INCDIR = $(APPDIR)$(DELIM)include$(DELIM)canutils
 
 CFLAGS += -std=c99 -DCANARD_ASSERT=DEBUGASSERT
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPS_INCDIR)}
+CFLAGS += ${INCDIR_PREFIX}$(APPS_INCDIR)
 
 CSRCS = $(LIBCANARDV0_SRCDIR)$(DELIM)canard.c $(LIBCANARDV0_DRVDIR)$(DELIM)canard_nuttx.c
 
diff --git a/canutils/libcanardv1/Makefile b/canutils/libcanardv1/Makefile
index 947d8426a..e32109840 100644
--- a/canutils/libcanardv1/Makefile
+++ b/canutils/libcanardv1/Makefile
@@ -40,7 +40,7 @@ O1HEAP_DRVDIR = $(O1HEAP_SRCDIR)$(DELIM)o1heap
 APPS_INCDIR = $(APPDIR)$(DELIM)include$(DELIM)canutils
 
 CFLAGS += -std=c11 -DCANARD_ASSERT=DEBUGASSERT -DCANARD_DSDL_CONFIG_LITTLE_ENDIAN=1
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPS_INCDIR)}
+CFLAGS += ${INCDIR_PREFIX}$(APPS_INCDIR)
 
 CSRCS  = $(LIBCANARDV1_DRVDIR)$(DELIM)canard.c $(LIBCANARDV1_DRVDIR)$(DELIM)canard_dsdl.c
 CSRCS += $(O1HEAP_DRVDIR)$(DELIM)o1heap.c
diff --git a/crypto/libtomcrypt/Make.defs b/crypto/libtomcrypt/Make.defs
index 258c9d744..a31d953f1 100644
--- a/crypto/libtomcrypt/Make.defs
+++ b/crypto/libtomcrypt/Make.defs
@@ -23,6 +23,6 @@ CONFIGURED_APPS += $(APPDIR)/crypto/libtomcrypt
 
 # It allows `<tomcrypt.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/libtomcrypt/libtomcrypt/src/headers}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/libtomcrypt/libtomcrypt/src/headers}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/libtomcrypt/libtomcrypt/src/headers
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/libtomcrypt/libtomcrypt/src/headers
 endif
diff --git a/crypto/mbedtls/Make.defs b/crypto/mbedtls/Make.defs
index ee7f7d736..7e0e5178b 100644
--- a/crypto/mbedtls/Make.defs
+++ b/crypto/mbedtls/Make.defs
@@ -23,8 +23,8 @@ CONFIGURED_APPS += $(APPDIR)/crypto/mbedtls
 
 # Allows `<mbedtls/<>.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/mbedtls/mbedtls/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/mbedtls/mbedtls/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/mbedtls/mbedtls/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/mbedtls/mbedtls/include
 
 CFLAGS += ${shell $(DEFINE) "$(CC)" MBEDTLS_CONFIG_FILE='"<crypto/mbedtls_config.h>"'}
 CXXFLAGS += ${shell $(DEFINE) "$(CC)" MBEDTLS_CONFIG_FILE='"<crypto/mbedtls_config.h>"'}
diff --git a/crypto/tinycrypt/Make.defs b/crypto/tinycrypt/Make.defs
index 8a898b399..d9349c9b2 100644
--- a/crypto/tinycrypt/Make.defs
+++ b/crypto/tinycrypt/Make.defs
@@ -20,6 +20,6 @@
 
 ifneq ($(CONFIG_TINYCRYPT),)
 CONFIGURED_APPS += $(APPDIR)/crypto/tinycrypt
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/tinycrypt/tinycrypt/lib/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/crypto/tinycrypt/tinycrypt/lib/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/tinycrypt/tinycrypt/lib/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/crypto/tinycrypt/tinycrypt/lib/include
 endif
diff --git a/examples/audio_rttl/Makefile b/examples/audio_rttl/Makefile
index 62c26f607..e70a50a88 100644
--- a/examples/audio_rttl/Makefile
+++ b/examples/audio_rttl/Makefile
@@ -37,7 +37,7 @@ AUDIODIR = $(SDKDIR)$(DELIM)modules$(DELIM)audio
 
 # Audio Example flags
 
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" "$(AUDIODIR)"}
+CXXFLAGS += ${INCDIR_PREFIX}"$(AUDIODIR)"
 CXXFLAGS += -D_POSIX
 
 include $(APPDIR)/Application.mk
diff --git a/examples/canardv0/Makefile b/examples/canardv0/Makefile
index 00f5f21ae..9e10611ea 100644
--- a/examples/canardv0/Makefile
+++ b/examples/canardv0/Makefile
@@ -25,7 +25,7 @@ PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = $(CONFIG_EXAMPLES_LIBCANARDV0_STACKSIZE)
 MODULE = $(CONFIG_EXAMPLES_LIBCANARDV0)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/include/canutils}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/include/canutils
 MAINSRC = canard_main.c
 
 include $(APPDIR)/Application.mk
diff --git a/examples/canardv1/Makefile b/examples/canardv1/Makefile
index 646d91792..2ad75d03b 100644
--- a/examples/canardv1/Makefile
+++ b/examples/canardv1/Makefile
@@ -25,7 +25,7 @@ PRIORITY = SCHED_PRIORITY_DEFAULT
 STACKSIZE = $(CONFIG_EXAMPLES_LIBCANARDV1_DAEMON_STACK_SIZE)
 MODULE = $(CONFIG_EXAMPLES_LIBCANARDV1)
 
-CFLAGS += -std=c11 ${shell $(INCDIR) "$(CC)" $(APPDIR)/include/canutils $(APPDIR)/include/o1heap}
+CFLAGS += -std=c11 ${INCDIR_PREFIX}$(APPDIR)/include/canutils $(APPDIR)/include/o1heap
 CSRCS = socketcan.c
 MAINSRC = canard_main.c
 
diff --git a/examples/pwfb/Makefile b/examples/pwfb/Makefile
index efe528f2f..51bc62fb9 100644
--- a/examples/pwfb/Makefile
+++ b/examples/pwfb/Makefile
@@ -23,7 +23,7 @@ include $(APPDIR)/Make.defs
 # NuttX per-window frame buffer graphics example.
 
 NXGLYPHS = $(APPDIR)$(DELIM)graphics$(DELIM)nxglyphs
-CFLAGS += ${shell $(INCDIR) "$(CC)" "$(NXGLYPHS)$(DELIM)include"}
+CFLAGS += ${INCDIR_PREFIX}"$(NXGLYPHS)$(DELIM)include"
 
 CSRCS = pwfb_events.c pwfb_motion.c
 MAINSRC = pwfb_main.c
diff --git a/examples/tcp_ipc_server/Makefile b/examples/tcp_ipc_server/Makefile
index 1744d121d..f181bea62 100644
--- a/examples/tcp_ipc_server/Makefile
+++ b/examples/tcp_ipc_server/Makefile
@@ -28,7 +28,7 @@ STACKSIZE = $(CONFIG_EXAMPLES_TCP_IPC_SERVER_STACKSIZE)
 MODULE    = $(CONFIG_EXAMPLES_TCP_IPC_SERVER)
 
 # SERVIDOR Example
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/examples/server_tcp/lorawan}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/examples/server_tcp/lorawan
 CSRCS  = uart_lorawan_layer.c protocol.c
 
 MAINSRC = tcp_ipc_server_main.c
diff --git a/gpsutils/minmea/Make.defs b/gpsutils/minmea/Make.defs
index e62f10703..849301868 100644
--- a/gpsutils/minmea/Make.defs
+++ b/gpsutils/minmea/Make.defs
@@ -20,6 +20,5 @@
 
 ifneq ($(CONFIG_GPSUTILS_MINMEA_LIB),)
 CONFIGURED_APPS += $(APPDIR)/gpsutils/minmea
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/gpsutils/minmea}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/gpsutils/minmea
 endif
diff --git a/graphics/libjpeg/Make.defs b/graphics/libjpeg/Make.defs
index 717a2e047..52c1f45d5 100644
--- a/graphics/libjpeg/Make.defs
+++ b/graphics/libjpeg/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_LIBJPEG),)
 CONFIGURED_APPS += $(APPDIR)/graphics/libjpeg
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/libjpeg/libjpeg}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/libjpeg/libjpeg}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/libjpeg/libjpeg
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/libjpeg/libjpeg
 endif
diff --git a/graphics/lvgl/Make.defs b/graphics/lvgl/Make.defs
index 5d289b063..7fa5292ad 100644
--- a/graphics/lvgl/Make.defs
+++ b/graphics/lvgl/Make.defs
@@ -23,11 +23,11 @@ CONFIGURED_APPS += $(APPDIR)/graphics/lvgl
 
 # It allows `<lvgl/lvgl.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/lvgl}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/lvgl}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/lvgl
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/lvgl
 
 # It allows `<lvgl.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/lvgl/lvgl}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/lvgl/lvgl}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/lvgl/lvgl
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/lvgl/lvgl
 endif
diff --git a/graphics/pdcurs34/Makefile b/graphics/pdcurs34/Makefile
index 56d3c9bb8..a97e00499 100644
--- a/graphics/pdcurs34/Makefile
+++ b/graphics/pdcurs34/Makefile
@@ -24,6 +24,6 @@ include $(APPDIR)/Make.defs
 include pdcurses/Make.defs
 include nuttx/Make.defs
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/graphics/pdcurs34/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/graphics/pdcurs34/include
 
 include $(APPDIR)/Application.mk
diff --git a/graphics/twm4nx/Makefile b/graphics/twm4nx/Makefile
index f6de5385a..0ec2f883a 100644
--- a/graphics/twm4nx/Makefile
+++ b/graphics/twm4nx/Makefile
@@ -22,7 +22,7 @@ include $(APPDIR)/Make.defs
 
 # Add path to cursor images to CXXFLAGS
 
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" "$(APPDIR)/graphics/nxglyphs/include"}
+CXXFLAGS += ${INCDIR_PREFIX}"$(APPDIR)/graphics/nxglyphs/include"
 
 # Twm4Nx built-in application info
 
diff --git a/import/Make.defs b/import/Make.defs
index f3f935188..0405e412b 100644
--- a/import/Make.defs
+++ b/import/Make.defs
@@ -27,10 +27,10 @@ include $(TOPDIR)/scripts/Make.defs
 # Compiler
 
 ARCHCRT0OBJ = $(call CONVERT_PATH,$(TOPDIR)$(DELIM)startup$(DELIM)crt0$(OBJEXT))
-ARCHINCLUDES += ${shell $(INCDIR) -s "$(CC)" $(TOPDIR)$(DELIM)include}
+ARCHINCLUDES += ${INCSYSDIR_PREFIX}$(TOPDIR)$(DELIM)include
 
-ARCHXXINCLUDES += ${shell $(INCDIR) -s "$(CC)" $(TOPDIR)$(DELIM)include}
-ARCHXXINCLUDES += ${shell $(INCDIR) -s "$(CC)" $(TOPDIR)$(DELIM)include$(DELIM)cxx}
+ARCHXXINCLUDES += ${INCSYSDIR_PREFIX}$(TOPDIR)$(DELIM)include
+ARCHXXINCLUDES += ${INCSYSDIR_PREFIX}$(TOPDIR)$(DELIM)include$(DELIM)cxx
 
 ARCHCFLAGS += -fno-common -pipe
 ARCHCXXFLAGS += -fno-common -nostdinc++ -pipe
diff --git a/interpreters/duktape/Make.defs b/interpreters/duktape/Make.defs
index 405b4516c..b9d4fbfd6 100644
--- a/interpreters/duktape/Make.defs
+++ b/interpreters/duktape/Make.defs
@@ -22,9 +22,7 @@ ifneq ($(CONFIG_INTERPRETERS_DUKTAPE),)
 CONFIGURED_APPS += $(APPDIR)/interpreters/duktape
 
 # It allows `<duktape/duktape.h>` import.
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/duktape/duktape/src-noline}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/duktape/duktape/src-noline}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/duktape/duktape/src-noline
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/duktape/duktape/src-noline
 
 endif
diff --git a/interpreters/ficl/Makefile b/interpreters/ficl/Makefile
index c478b10d4..6b3308c6f 100644
--- a/interpreters/ficl/Makefile
+++ b/interpreters/ficl/Makefile
@@ -30,7 +30,7 @@ include $(APPDIR)/Make.defs
 
 # Include paths
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(BUILDDIR)/$(FICL_SUBDIR) $(BUILDDIR)/src}
+CFLAGS += ${INCDIR_PREFIX}$(BUILDDIR)/$(FICL_SUBDIR) $(BUILDDIR)/src
 
 # Source Files
 
diff --git a/interpreters/lua/Make.defs b/interpreters/lua/Make.defs
index 0ab12140c..277e48f5f 100644
--- a/interpreters/lua/Make.defs
+++ b/interpreters/lua/Make.defs
@@ -23,9 +23,9 @@ CONFIGURED_APPS += $(APPDIR)/interpreters/lua
 
 # Enable <lua.h> and <lauxlib.h> includes.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-	$(APPDIR)/interpreters/lua/lua-$(CONFIG_INTERPRETER_LUA_VERSION)/src}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-	$(APPDIR)/interpreters/lua/lua-$(CONFIG_INTERPRETER_LUA_VERSION)/src}
+CFLAGS += ${INCDIR_PREFIX}\
+	$(APPDIR)/interpreters/lua/lua-$(CONFIG_INTERPRETER_LUA_VERSION)/src
+CXXFLAGS += ${INCDIR_PREFIX}\
+	$(APPDIR)/interpreters/lua/lua-$(CONFIG_INTERPRETER_LUA_VERSION)/src
 
 endif
diff --git a/interpreters/quickjs/Make.defs b/interpreters/quickjs/Make.defs
index c0f9a7da6..d08b683fa 100644
--- a/interpreters/quickjs/Make.defs
+++ b/interpreters/quickjs/Make.defs
@@ -22,9 +22,7 @@ ifneq ($(CONFIG_INTERPRETERS_QUICKJS),)
 CONFIGURED_APPS += $(APPDIR)/interpreters/quickjs
 
 # It allows `<quickjs/quickjs.h>` import.
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/quickjs}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/quickjs}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/quickjs
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/quickjs
 
 endif
diff --git a/interpreters/wamr/Make.defs b/interpreters/wamr/Make.defs
index c09e5d2cb..0c53a3614 100644
--- a/interpreters/wamr/Make.defs
+++ b/interpreters/wamr/Make.defs
@@ -21,9 +21,7 @@
 ifneq ($(CONFIG_INTERPRETERS_WAMR),)
 CONFIGURED_APPS += $(APPDIR)/interpreters/wamr
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/wamr/wamr/core/iwasm/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/wamr/wamr/core/iwasm/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/wamr/wamr/core/iwasm/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/wamr/wamr/core/iwasm/include
 
 endif
diff --git a/interpreters/wasm3/Make.defs b/interpreters/wasm3/Make.defs
index a9c7c3c04..db0e96c8c 100644
--- a/interpreters/wasm3/Make.defs
+++ b/interpreters/wasm3/Make.defs
@@ -21,9 +21,7 @@
 ifneq ($(CONFIG_INTERPRETERS_WASM3),)
 CONFIGURED_APPS += $(APPDIR)/interpreters/wasm3
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/wasm3/wasm3/source}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/interpreters/wasm3/wasm3/source}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/wasm3/wasm3/source
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/interpreters/wasm3/wasm3/source
 
 endif
diff --git a/math/libtommath/Make.defs b/math/libtommath/Make.defs
index 2fc71d5ae..6531ad3ae 100644
--- a/math/libtommath/Make.defs
+++ b/math/libtommath/Make.defs
@@ -23,6 +23,6 @@ CONFIGURED_APPS += $(APPDIR)/math/libtommath
 
 # It allows `<tommath.h>` import.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/math/libtommath/libtommath}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/math/libtommath/libtommath}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/math/libtommath/libtommath
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/math/libtommath/libtommath
 endif
diff --git a/mlearning/cmsis/Make.defs b/mlearning/cmsis/Make.defs
index 3ec875379..e36031b92 100644
--- a/mlearning/cmsis/Make.defs
+++ b/mlearning/cmsis/Make.defs
@@ -23,6 +23,6 @@ CONFIGURED_APPS += $(APPDIR)/mlearning/cmsis
 
 include $(wildcard $(APPDIR)/mlearning/cmsis/*/Make.defs)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/Core/Include/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/Core/Include/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/Core/Include/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/Core/Include/
 endif
diff --git a/mlearning/cmsis/libcmsisdsp/Make.defs b/mlearning/cmsis/libcmsisdsp/Make.defs
index efafee7d1..de9d8ea51 100644
--- a/mlearning/cmsis/libcmsisdsp/Make.defs
+++ b/mlearning/cmsis/libcmsisdsp/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_CMSIS_DSP),)
 CONFIGURED_APPS += $(APPDIR)/mlearning/cmsis/libcmsisdsp
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/Include/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/Include/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/Include/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/Include/
 endif
diff --git a/mlearning/cmsis/libcmsisdsp/Makefile b/mlearning/cmsis/libcmsisdsp/Makefile
index d6ec0c813..8fd731685 100644
--- a/mlearning/cmsis/libcmsisdsp/Makefile
+++ b/mlearning/cmsis/libcmsisdsp/Makefile
@@ -31,8 +31,8 @@ CFLAGS += -D__FPU_PRESENT=1U
 CXXFLAGS += -D__FPU_PRESENT=1U
 endif
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/PrivateInclude/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/PrivateInclude/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/PrivateInclude/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/DSP/PrivateInclude/
 
 CMSIS5_DSP := ../CMSIS_5/CMSIS/DSP/Source
 CSRCS += SVMFunctions.c
diff --git a/mlearning/cmsis/libcmsisnn/Make.defs b/mlearning/cmsis/libcmsisnn/Make.defs
index 5953c5a94..187ff5557 100644
--- a/mlearning/cmsis/libcmsisnn/Make.defs
+++ b/mlearning/cmsis/libcmsisnn/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_CMSIS_NN),)
 CONFIGURED_APPS += $(APPDIR)/mlearning/cmsis/libcmsisnn
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/NN/Include/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/NN/Include/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/NN/Include/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/cmsis/CMSIS_5/CMSIS/NN/Include/
 endif
diff --git a/mlearning/darknet/Make.defs b/mlearning/darknet/Make.defs
index 0e95563bd..b06d5b534 100644
--- a/mlearning/darknet/Make.defs
+++ b/mlearning/darknet/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_DARKNET_YOLO),)
 CONFIGURED_APPS += $(APPDIR)/mlearning/darknet
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/darknet/darknet/include/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/darknet/darknet/include/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/darknet/darknet/include/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/darknet/darknet/include/
 endif
diff --git a/mlearning/libnnablart/Make.defs b/mlearning/libnnablart/Make.defs
index b4979b7ac..8733fa2c9 100644
--- a/mlearning/libnnablart/Make.defs
+++ b/mlearning/libnnablart/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_NNABLA_RT),)
 CONFIGURED_APPS += $(APPDIR)/mlearning/libnnablart
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/libnnablart/nnabla-c-runtime/include/}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/mlearning/libnnablart/nnabla-c-runtime/include/}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/libnnablart/nnabla-c-runtime/include/
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/mlearning/libnnablart/nnabla-c-runtime/include/
 endif
diff --git a/modbus/ascii/Make.defs b/modbus/ascii/Make.defs
index fb1975938..15647c900 100644
--- a/modbus/ascii/Make.defs
+++ b/modbus/ascii/Make.defs
@@ -24,6 +24,6 @@ CSRCS += mbascii.c
 
 DEPPATH += --dep-path ascii
 VPATH += :ascii
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/modbus/ascii}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/modbus/ascii
 
 endif
diff --git a/modbus/functions/Make.defs b/modbus/functions/Make.defs
index 75e3c009a..9027dce62 100644
--- a/modbus/functions/Make.defs
+++ b/modbus/functions/Make.defs
@@ -31,4 +31,4 @@ endif
 
 DEPPATH += --dep-path functions
 VPATH += :functions
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/modbus/functions}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/modbus/functions
diff --git a/modbus/rtu/Make.defs b/modbus/rtu/Make.defs
index 5051c6c40..bc5ce1829 100644
--- a/modbus/rtu/Make.defs
+++ b/modbus/rtu/Make.defs
@@ -38,6 +38,6 @@ endif
 
 DEPPATH += --dep-path rtu
 VPATH += :rtu
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/modbus/rtu}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/modbus/rtu
 
 endif
diff --git a/modbus/tcp/Make.defs b/modbus/tcp/Make.defs
index f38291084..9503ca16b 100644
--- a/modbus/tcp/Make.defs
+++ b/modbus/tcp/Make.defs
@@ -24,6 +24,6 @@ CSRCS += mbtcp.c
 
 DEPPATH += --dep-path tcp
 VPATH += :tcp
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/modbus/tcp}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/modbus/tcp
 
 endif
diff --git a/netutils/cjson/Makefile b/netutils/cjson/Makefile
index f2b551087..d5ad647a0 100644
--- a/netutils/cjson/Makefile
+++ b/netutils/cjson/Makefile
@@ -40,7 +40,7 @@ CJSON_SRCDIR = $(CJSON_UNPACKNAME)
 
 APPS_INCDIR = $(APPDIR)$(DELIM)include$(DELIM)netutils
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPS_INCDIR)}
+CFLAGS += ${INCDIR_PREFIX}$(APPS_INCDIR)
 CFLAGS += -DCJSON_INCLUDE_CONFIG_H
 
 CSRCS = $(CJSON_SRCDIR)$(DELIM)cJSON.c
diff --git a/netutils/cwebsocket/Make.defs b/netutils/cwebsocket/Make.defs
index 0c421cd37..9d068ef8e 100644
--- a/netutils/cwebsocket/Make.defs
+++ b/netutils/cwebsocket/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_CWEBSOCKET),)
 CONFIGURED_APPS += $(APPDIR)/netutils/cwebsocket
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/netutils/cwebsocket/cwebsocket}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/netutils/cwebsocket/cwebsocket}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/netutils/cwebsocket/cwebsocket
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/netutils/cwebsocket/cwebsocket
 endif
diff --git a/netutils/mqttc/Make.defs b/netutils/mqttc/Make.defs
index b3401b7cb..7c9d235d2 100644
--- a/netutils/mqttc/Make.defs
+++ b/netutils/mqttc/Make.defs
@@ -21,10 +21,8 @@
 ifneq ($(CONFIG_NETUTILS_MQTTC),)
 CONFIGURED_APPS += $(APPDIR)/netutils/mqttc
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-	$(APPDIR)/netutils/mqttc/MQTT-C/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-    $(APPDIR)/netutils/mqttc/MQTT-C/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/netutils/mqttc/MQTT-C/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/netutils/mqttc/MQTT-C/include
 
 ifneq ($(CONFIG_NETUTILS_MQTTC_WITH_MBEDTLS),)
 CFLAGS += -DMQTT_USE_MBEDTLS
diff --git a/netutils/thttpd/Makefile b/netutils/thttpd/Makefile
index 4fc574160..8c637ec79 100644
--- a/netutils/thttpd/Makefile
+++ b/netutils/thttpd/Makefile
@@ -38,7 +38,7 @@ endif
 
 ifeq ($(CONFIG_THTTPD_BINFS),y)
   CSRCS +=  phf.c redirect.c ssi.c
-  CFLAGS += ${shell $(INCDIR) "$(CC)" "$(APPDIR)$(DELIM)netutils$(DELIM)thttpd"}
+  CFLAGS += ${INCDIR_PREFIX}"$(APPDIR)$(DELIM)netutils$(DELIM)thttpd"
   DEPPATHS += --dep-path cgi-src
   VPATH += :cgi-src
 
diff --git a/netutils/thttpd/cgi-src/Makefile b/netutils/thttpd/cgi-src/Makefile
index 73bd0d614..1d215c4fc 100644
--- a/netutils/thttpd/cgi-src/Makefile
+++ b/netutils/thttpd/cgi-src/Makefile
@@ -20,7 +20,7 @@
 
 include $(APPDIR)/Make.defs
 
-CFLAGS		+= ${shell $(INCDIR) "$(CC)" "$(APPDIR)$(DELIM)netutils$(DELIM)thttpd"}
+CFLAGS		+= ${INCDIR_PREFIX}"$(APPDIR)$(DELIM)netutils$(DELIM)thttpd"
 CGIBINDIR	= $(APPDIR)/netutils/thttpd/cgi-bin
 CLEANFILES	= *.o redirect ssi phf
 
diff --git a/system/argtable3/Make.defs b/system/argtable3/Make.defs
index 524feef89..8ee817972 100644
--- a/system/argtable3/Make.defs
+++ b/system/argtable3/Make.defs
@@ -21,6 +21,6 @@
 ifneq ($(CONFIG_SYSTEM_ARGTABLE3),)
 CONFIGURED_APPS += $(APPDIR)/system/argtable3
 
-CFLAGS   += ${shell $(INCDIR) "$(CC)" "$(APPDIR)/system/argtable3/argtable3/src"}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" "$(APPDIR)/system/argtable3/argtable3/src"}
+CFLAGS   += ${INCDIR_PREFIX}"$(APPDIR)/system/argtable3/argtable3/src"
+CXXFLAGS += ${INCDIR_PREFIX}"$(APPDIR)/system/argtable3/argtable3/src"
 endif
diff --git a/system/embedlog/Makefile b/system/embedlog/Makefile
index a4741deb1..91c4a8c17 100644
--- a/system/embedlog/Makefile
+++ b/system/embedlog/Makefile
@@ -32,7 +32,7 @@ EMBEDLOG_EXT = tar.gz
 EMBEDLOG_SOURCES = embedlog-$(EMBEDLOG_VERSION)
 EMBEDLOG_TARBALL = $(EMBEDLOG_SOURCES).$(EMBEDLOG_EXT)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)$(DELIM)include$(DELIM)system}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)$(DELIM)include$(DELIM)system
 
 CSRCS = $(EMBEDLOG_SOURCES)/src/el-options.c \
 	$(EMBEDLOG_SOURCES)/src/el-perror.c \
diff --git a/system/hexed/Makefile b/system/hexed/Makefile
index 45f9f8e62..aa80b4ad6 100644
--- a/system/hexed/Makefile
+++ b/system/hexed/Makefile
@@ -31,7 +31,7 @@ CSRCS   = bfile.c cmdargs.c hexcopy.c hexdump.c hexenter.c hexhelp.c
 CSRCS  += hexinsert.c hexmove.c hexremove.c hexword.c
 MAINSRC = hexed.c
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" include}
+CFLAGS += ${INCDIR_PREFIX}include
 
 VPATH += :src
 DEPPATH += --dep-path src
diff --git a/system/libuv/Make.defs b/system/libuv/Make.defs
index 77ecc7fee..740c5ef84 100644
--- a/system/libuv/Make.defs
+++ b/system/libuv/Make.defs
@@ -23,9 +23,7 @@ CONFIGURED_APPS += $(APPDIR)/system/libuv
 
 # Enable <uv.h> include.
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" \
-	$(APPDIR)/system/libuv/libuv/include}
-CXXFLAGS += ${shell $(INCDIR) "$(CC)" \
-	$(APPDIR)/system/libuv/libuv/include}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/system/libuv/libuv/include
+CXXFLAGS += ${INCDIR_PREFIX}$(APPDIR)/system/libuv/libuv/include
 
 endif
diff --git a/system/psmq/Makefile b/system/psmq/Makefile
index 258d3156c..72afd35a2 100644
--- a/system/psmq/Makefile
+++ b/system/psmq/Makefile
@@ -32,8 +32,8 @@ PSMQ_EXT = tar.gz
 PSMQ_SOURCES = psmq-$(PSMQ_VERSION)
 PSMQ_TARBALL = $(PSMQ_SOURCES).$(PSMQ_EXT)
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)$(DELIM)include$(DELIM)system}
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)$(DELIM)system$(DELIM)psmq$(DELIM)$(PSMQ_SOURCES)}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)$(DELIM)include$(DELIM)system
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)$(DELIM)system$(DELIM)psmq$(DELIM)$(PSMQ_SOURCES)
 
 # mandatory source files to compile
 CSRCS = $(PSMQ_SOURCES)/lib/psmq.c \
diff --git a/system/uorb/Make.defs b/system/uorb/Make.defs
index c80bbdf4a..5d4e230ce 100644
--- a/system/uorb/Make.defs
+++ b/system/uorb/Make.defs
@@ -20,8 +20,6 @@
 
 ifneq ($(CONFIG_UORB),)
 CONFIGURED_APPS += $(APPDIR)/system/uorb
-CFLAGS          += ${shell $(INCDIR) "$(CC)" \
-                   $(APPDIR)/system/uorb/}
-CXXFLAGS        += ${shell $(INCDIR) "$(CC)" \
-                   $(APPDIR)/system/uorb/}
+CFLAGS          += ${INCDIR_PREFIX}$(APPDIR)/system/uorb/
+CXXFLAGS        += ${INCDIR_PREFIX}$(APPDIR)/system/uorb/
 endif
diff --git a/testing/unity/Makefile b/testing/unity/Makefile
index f57624f34..4a3790328 100644
--- a/testing/unity/Makefile
+++ b/testing/unity/Makefile
@@ -40,7 +40,7 @@ UNITY_SRCDIR = $(UNITY_UNPACKNAME)$(DELIM)src
 
 APPS_INCDIR = $(APPDIR)$(DELIM)include$(DELIM)testing
 
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPS_INCDIR)}
+CFLAGS += ${INCDIR_PREFIX}$(APPS_INCDIR)
 CFLAGS += -DUNITY_INCLUDE_CONFIG_H
 
 CSRCS = $(UNITY_SRCDIR)$(DELIM)unity.c
diff --git a/wireless/iwpan/src/Make.defs b/wireless/iwpan/src/Make.defs
index 3be4d58db..3725a4110 100644
--- a/wireless/iwpan/src/Make.defs
+++ b/wireless/iwpan/src/Make.defs
@@ -24,6 +24,6 @@ MAINSRC = iwpan.c
 
 DEPPATH += --dep-path src
 VPATH += :src
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/wireless/iwpan/src}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/wireless/iwpan/src
 
 endif
diff --git a/wireless/wapi/src/Make.defs b/wireless/wapi/src/Make.defs
index 6ee9c36a4..df2ddb3ad 100644
--- a/wireless/wapi/src/Make.defs
+++ b/wireless/wapi/src/Make.defs
@@ -28,6 +28,6 @@ endif
 
 DEPPATH += --dep-path src
 VPATH += :src
-CFLAGS += ${shell $(INCDIR) "$(CC)" $(APPDIR)/wireless/wapi/src}
+CFLAGS += ${INCDIR_PREFIX}$(APPDIR)/wireless/wapi/src
 
 endif