diff --git a/makefiles/Makefile.common b/makefiles/Makefile.common
index ee618071..793b089e 100644
--- a/makefiles/Makefile.common
+++ b/makefiles/Makefile.common
@@ -24,15 +24,15 @@ ifndef TRICK_SFLAGS
  export TRICK_SFLAGS :=
 endif
 
-export TRICK_CFLAGS
-export TRICK_CXXFLAGS
-export TRICK_LDFLAGS
-export TRICK_SFLAGS
-export TRICK_ICG_EXCLUDE
-export TRICK_ICG_NOCOMMENT
-export TRICK_SWIG_EXCLUDE
-export TRICK_PYTHON_PATH
-export TRICK_GTE_EXT
+export TRICK_CFLAGS := $(TRICK_CFLAGS)
+export TRICK_CXXFLAGS := $(TRICK_CXXFLAGS)
+export TRICK_LDFLAGS := $(TRICK_LDFLAGS)
+export TRICK_SFLAGS := $(TRICK_SFLAGS)
+export TRICK_ICG_EXCLUDE := $(TRICK_ICG_EXCLUDE)
+export TRICK_ICG_NOCOMMENT := $(TRICK_ICG_NOCOMMENT)
+export TRICK_SWIG_EXCLUDE := $(TRICK_SWIG_EXCLUDE)
+export TRICK_PYTHON_PATH := $(TRICK_PYTHON_PATH)
+export TRICK_GTE_EXT := $(TRICK_GTE_EXT)
 export TRICK_HOST_CPU := $(shell export TRICK_CC=$(TRICK_CC) && $(TRICK_HOME)/bin/gte TRICK_HOST_CPU)
 
 ifndef CONFIG_MK