diff --git a/boards/sim/sim/sim/scripts/Make.defs b/boards/sim/sim/sim/scripts/Make.defs
index ef4b1462b9..686d2dd660 100644
--- a/boards/sim/sim/sim/scripts/Make.defs
+++ b/boards/sim/sim/sim/scripts/Make.defs
@@ -78,13 +78,12 @@ else ifeq ($(CONFIG_MM_KASAN_ALL),y)
 endif
 
 ifeq ($(CONFIG_SIM_UBSAN),y)
-  ARCHOPTIMIZATION += $(CONFIG_MM_UBSAN_OPTION)
+  ARCHOPTIMIZATION += -fsanitize=undefined
 else ifeq ($(CONFIG_MM_UBSAN_ALL),y)
   ARCHOPTIMIZATION += $(CONFIG_MM_UBSAN_OPTION)
-endif
-
-ifeq ($(CONFIG_MM_UBSAN_TRAP_ON_ERROR),y)
-  ARCHOPTIMIZATION += -fsanitize-undefined-trap-on-error
+  ifeq ($(CONFIG_MM_UBSAN_TRAP_ON_ERROR),y)
+    ARCHOPTIMIZATION += -fsanitize-undefined-trap-on-error
+  endif
 endif
 
 # Add -fno-common because macOS "ld -r" doesn't seem to pick objects
diff --git a/mm/Kconfig b/mm/Kconfig
index d604703581..21950a696d 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -212,7 +212,7 @@ config MM_UBSAN_ALL
 
 config MM_UBSAN_OPTION
 	string "UBSan options"
-	depends on MM_UBSAN || SIM_UBSAN
+	depends on MM_UBSAN
 	default "-fsanitize=undefined"
 	---help---
 		This option activates specified UBSan instrumentation. Please