diff --git a/Makefile.am b/Makefile.am
index 4af7f566c..99da6b96b 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -86,7 +86,7 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
-scripts/symbols.out scripts/pngwin.out: png.h pngconf.h scripts/pnglibconf.h
+scripts/symbols.out scripts/pngwin.out: png.h pngconf.h scripts/pnglibconf.h.prebuilt
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -100,7 +100,7 @@ pngwin.def: scripts/pngwin.out
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
-scripts/pnglibconf.h:
+scripts/pnglibconf.h.prebuilt:
 	@echo "This is a machine generated file, but if you want to make" >&2
 	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
 	@exit 1
diff --git a/Makefile.in b/Makefile.in
index bf5766d2a..80792c1f3 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -1259,7 +1259,7 @@ $(PNGLIB_BASENAME)-config: libpng-config
 	cp libpng-config $@
 
 scripts/sym.out scripts/vers.out: png.h pngconf.h pnglibconf.h
-scripts/symbols.out scripts/pngwin.out: png.h pngconf.h scripts/pnglibconf.h
+scripts/symbols.out scripts/pngwin.out: png.h pngconf.h scripts/pnglibconf.h.prebuilt
 
 libpng.sym: scripts/sym.out
 	rm -f $@
@@ -1273,7 +1273,7 @@ pngwin.def: scripts/pngwin.out
 pnglibconf.h: pnglibconf.out
 	rm -f $@
 	cp $? $@
-scripts/pnglibconf.h:
+scripts/pnglibconf.h.prebuilt:
 	@echo "This is a machine generated file, but if you want to make" >&2
 	@echo "a new one simply make 'scripts/pnglibconf.out' and copy that" >&2
 	@exit 1