diff --git a/source/Makefile.mk b/source/Makefile.mk
index c332e5232..13db62bf9 100644
--- a/source/Makefile.mk
+++ b/source/Makefile.mk
@@ -8,10 +8,10 @@
 # Modify to enable/disable specific features
 
 # Use the free vestige header instead of the official VST SDK
-CARLA_VESTIGE_HEADER ?= true
+CARLA_VESTIGE_HEADER = true
 
 # Enable experimental plugins, don't complain if the build fails when using this!
-EXPERIMENTAL_PLUGINS ?= false
+EXPERIMENTAL_PLUGINS = false
 
 # --------------------------------------------------------------
 # DO NOT MODIFY PAST THIS POINT!