diff --git a/scripts/makefile.darwin b/scripts/makefile.darwin
index c55f817..55e9222 100644
--- a/scripts/makefile.darwin
+++ b/scripts/makefile.darwin
@@ -23,7 +23,7 @@
 RANLIB=ranlib
 
 PNGMAJ = 0
-PNGMIN = 1.2.4beta2
+PNGMIN = 1.2.4beta3
 PNGVER = $(PNGMAJ).$(PNGMIN)
 LIBNAME = libpng12
 
@@ -156,8 +156,19 @@
 
 install: install-static install-shared install-man install-config
 
+# If you installed in $(DESTDIR), test-installed won't work until you
+# move the library to its final location.
+
+test-installed:
+	$(CC) $(CFLAGS) \
+	   `$(BINPATH)/libpng12-config --cppflags --cflags` pngtest.c \
+	   -L$(ZLIBLIB) \
+	   -o pngtesti `$(BINPATH)/libpng12-config --ldflags --libs`
+	pngtesti pngtest.png
+
 clean:
-	rm -f *.o libpng.a $(LIBNAME).*dylib pngtest pngout.png
+	rm -f *.o libpng.a pngtest pngout.png libpng.pc libpng-config \
+	$(LIBNAME).*dylib pngtesti
 
 DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO
 writelock: