1 files changed, 1 insertions, 2 deletions
diff --git a/Makefile b/Makefile
index d24104b..a384ecf 100644
--- a/Makefile
+++ b/Makefile
@@ -6,8 +6,7 @@ GHDL=ghdl
 YOSYS_CONFIG=yosys-config
 SOEXT=so
 
-LDFLAGS=
-CFLAGS=-O
+CFLAGS ?= -O
 
 LIBGHDL_LIB:=$(shell $(GHDL) --libghdl-library-path)
 LIBGHDL_INC:=$(shell $(GHDL) --libghdl-include-dir)