diff --git a/demos/STM32/RT-STM32F407-DISCOVERY-MEMS/Makefile b/demos/STM32/RT-STM32F407-DISCOVERY-MEMS/Makefile
index ea4a12301..d705ea5c6 100644
--- a/demos/STM32/RT-STM32F407-DISCOVERY-MEMS/Makefile
+++ b/demos/STM32/RT-STM32F407-DISCOVERY-MEMS/Makefile
@@ -211,7 +211,7 @@ UINCDIR =
 ULIBDIR =
 
 # List all user libraries here
-ULIBS =
+ULIBS = -lm
 
 #
 # End of user defines