diff --git a/arduino/Makefile b/arduino/Makefile
index e652707..31a3b56 100644
--- a/arduino/Makefile
+++ b/arduino/Makefile
@@ -21,4 +21,8 @@ ARDUINO_DIR ?= $(HOME)/arduino/arduino-1.8.5
 
 USER_LIB_PATH := $(PWD)
 
+# We don't need exact math. Let gcc be a bit more agressive.
+CFLAGS += -ffast-math
+CXXFLAGS += -ffast-math
+
 include $(ARDMK_DIR)/Arduino.mk