diff --git a/Makefile b/Makefile
index cd96bf4..ce2b47c 100644
--- a/Makefile
+++ b/Makefile
@@ -101,7 +101,7 @@ endif
 
 # used libraries
 LIBNAME = opencm3_stm32f1
-LDLIBS += -l$(LIBNAME)
+LDLIBS += -lm -l$(LIBNAME)
 LDLIBS += -Wl,--start-group -lc -lgcc -lnosys -Wl,--end-group
 
 # device specific flags