diff --git a/makepanda/makepanda.py b/makepanda/makepanda.py
index b2e0f9d508..ed831e948e 100755
--- a/makepanda/makepanda.py
+++ b/makepanda/makepanda.py
@@ -4864,9 +4864,11 @@ function have16installed() {
     print >>dist, '</installer-script>'
     dist.close()
     
-    oscmd('hdiutil create Panda3D-rw.dmg -srcfolder dstroot/Panda3D')
-    oscmd('hdiutil convert Panda3D-rw.dmg -format UDBZ -o Panda3D-%s.dmg' % VERSION)
+    oscmd('hdiutil create Panda3D-rw.dmg -srcfolder dstroot/Panda3D', True)
+    oscmd('hdiutil convert Panda3D-rw.dmg -format UDBZ -o Panda3D-%s.dmg' % VERSION, True)
     oscmd('rm -f Panda3D-rw.dmg')
+    if os.path.isfile("Panda3D-%s.dmg" % VERSION):
+        exit("Failed to create installer!")
 
 if (INSTALLER != 0):
     ProgressOutput(100.0, "Building installer")