diff --git a/tools/ucl/Makefile b/tools/ucl/Makefile
index a555e727ec..166ce39927 100644
--- a/tools/ucl/Makefile
+++ b/tools/ucl/Makefile
@@ -6,12 +6,12 @@
 #                     \/            \/     \/    \/            \/
 # $Id$
 #
-CFLAGS = -O2 -Iinclude
+CFLAGS+ = -O2 -Iinclude
 
 TARGET = ../uclpack
 
 $(TARGET): uclpack.o src/libucl.a
-	$(CC) uclpack.o src/libucl.a -o $(TARGET)
+	$(CC) $(CFLAGS) uclpack.o src/libucl.a -o $(TARGET)
 
 uclpack.o: uclpack.c
 
@@ -20,4 +20,4 @@ src/libucl.a:
 
 clean:
 	rm -f $(TARGET) uclpack.o
-	$(MAKE) -C src clean
\ No newline at end of file
+	$(MAKE) -C src clean
diff --git a/tools/ucl/src/Makefile b/tools/ucl/src/Makefile
index ab6b6c9c0b..c010cdf23c 100644
--- a/tools/ucl/src/Makefile
+++ b/tools/ucl/src/Makefile
@@ -6,7 +6,7 @@
 #                     \/            \/     \/    \/            \/
 # $Id$
 #
-CFLAGS = -I../include
+CFLAGS += -I../include
 
 ifndef V
 SILENT = @