diff --git a/make/defs.mk b/make/defs.mk
index 7f125b25..58296177 100644
--- a/make/defs.mk
+++ b/make/defs.mk
@@ -356,7 +356,7 @@ CPP                   ?= g++
 ifeq ($(USE_GFILTER),true)
 	GFILT          = sh $(firstword $(wildcard $(MODDIR)/contrib/gfilt/gfilt $(MODDIR)/bin/gfilt))
 	ifneq ($(strip $(GFILT)),sh)
-		CPP    = $(GFILT)
+		GPP    = $(GFILT)
 	endif
 endif