diff --git a/Makefile b/Makefile
index e413d8b..05e6623 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ KRKMODS  = $(wildcard modules/*.krk modules/*/*.krk modules/*/*/*.krk)
 
 all: ${TARGET} ${MODULES} ${TOOLS} ${GENMODS}
 
-ifneq ($(shell tools/can-floor-without-libm.sh $(CC)),yes)
+ifneq ($(shell tools/can-floor-without-libm.sh "$(CC) $(CFLAGS)"),yes)
   LDLIBS += -lm
 endif