diff --git a/mm/tlsf/Make.defs b/mm/tlsf/Make.defs
index c342c36191..c536c2890b 100644
--- a/mm/tlsf/Make.defs
+++ b/mm/tlsf/Make.defs
@@ -38,7 +38,7 @@ distclean::
 
 CSRCS += mm_tlsf.c tlsf.c
 
-CFLAGS += ${shell $(DEFINE) "$(CC)" tlsf_printf=\"if\(0\)printf\"}
+CFLAGS += ${DEFINE_PREFIX}tlsf_printf=if\(0\)printf
 
 # Add the tlsf directory to the build