diff --git a/Makefile b/Makefile
index a2b35edc2..b343bec0f 100644
--- a/Makefile
+++ b/Makefile
@@ -60,4 +60,4 @@ endif
 
 include mk/lib.mk
 
-GLOBAL_CXXFLAGS += -g -Wall -include config.h -std=c++2a -I src
+GLOBAL_CXXFLAGS += -g -Wall -include $(buildprefix)config.h -std=c++2a -I src