diff --git a/case/Makefile b/case/Makefile
index 5c63246..561cd7a 100644
--- a/case/Makefile
+++ b/case/Makefile
@@ -9,6 +9,8 @@ OPENSCAD	= /usr/bin/openscad
 all: $(SCAD_MODELS) $(STL_MODELS)
 
 top-keyboard.scad: SCAD_INPUT = top.scad
+top-keyboard.scad: top.scad
+
 top-outline.scad:  SCAD_INPUT = outline.scad
 top-outline.scad: outline.scad