diff --git a/C/Makefile b/C/Makefile
index 9a4fb56..ebbfec2 100644
--- a/C/Makefile
+++ b/C/Makefile
@@ -12,6 +12,9 @@ headers:
 sources:
 	make -C src sources
 
+build:
+	mkdir -p $(BUILD_DIR)
+
 clean:
 	make -C include clean
 	make -C src clean
diff --git a/C/src/Makefile b/C/src/Makefile
index c51a816..2bec3bc 100644
--- a/C/src/Makefile
+++ b/C/src/Makefile
@@ -1,8 +1,7 @@
 
 
 
-SRC=codata_constants_2010.c codata_constants_2014 codata_constants_2018 codata_constants_2022
+SRC=codata_constants_2010.c codata_constants_2014.c codata_constants_2018.c codata_constants_2022.c
 
 
 sources: $(SRC)
-