diff --git a/Tuprules.tup b/Tuprules.tup
index 06562087..c9c7c6df 100644
--- a/Tuprules.tup
+++ b/Tuprules.tup
@@ -37,8 +37,8 @@ CFLAGS_@(OPENXR) += -DLOVR_USE_OPENXR
 CFLAGS_@(OCULUS) += -DLOVR_USE_OCULUS
 CFLAGS_@(OCULUS) += -I@(OCULUS_PATH)/LibOVR/Include
 CFLAGS_@(VRAPI) += -DLOVR_USE_OCULUS_MOBILE
-CFLAGS_@(WEBVR) += LOVR_USE_WEBVR
-CFLAGS_@(LEAP) += LOVR_USE_LEAP
+CFLAGS_@(WEBVR) += -DLOVR_USE_WEBVR
+CFLAGS_@(LEAP) += -DLOVR_USE_LEAP
 
 ## Platforms
 # A little gnarly, but basically you can set CONFIG_PLATFORM to pick a specific one, otherwise