diff --git a/lib/filter/ghdl/fir_semi_parallel.inc b/lib/filter/ghdl/fir_semi_parallel.inc
index 3915674..8c14cd6 100644
--- a/lib/filter/ghdl/fir_semi_parallel.inc
+++ b/lib/filter/ghdl/fir_semi_parallel.inc
@@ -15,7 +15,7 @@ SRCS += $(LIB_PATH)/filter/src/delay_line.vhd
 SRCS += $(LIB_PATH)/filter/src/fir_semi_parallel.vhd
 
 # -----------------------------------------------------------
-$(PKG_NAME)_SRCS := $(addprefix $(CUR_PATH)/,$(_SRC))
+$(PKG_NAME)_SRCS := $(addprefix $(CUR_PATH)/,$(SRCS))
 
 SRCS := 
 CUR_PATH :=