diff --git a/prism/etc/scripts/prism-auto b/prism/etc/scripts/prism-auto
index db02b12d..16a4ae13 100755
--- a/prism/etc/scripts/prism-auto
+++ b/prism/etc/scripts/prism-auto
@@ -309,7 +309,7 @@ def runPrism(args, dir=""):
         if options.testAll: args.append("-testall")
         else: args.append("-test")
     if options.nailgun:
-        prismArgs = ["ngprism"] + args
+        prismArgs = [options.ngprism] + args
     else:
         prismArgs = [options.prismExec] + args
     if options.echo or options.echoFull:
@@ -632,7 +632,7 @@ def printUsage():
 
 def signal_handler(signal, frame):
     if options.nailgun:
-        subprocess.Popen(["ngprism", "stop"]).wait()
+        subprocess.Popen([options.ngprism, "stop"]).wait()
     sys.exit(1)
 
 # Main program
@@ -650,6 +650,7 @@ parser.add_option("-x", "--extra", action="append", dest="extraArgs", metavar="X
 parser.add_option("-t", "--test", action="store_true", dest="test", default=False, help="Run in test mode")
 parser.add_option("-w", "--show-warnings", action="store_true", dest="showWarnings", default=False, help="Show warnings (as well as errors) when in test mode")
 parser.add_option("--nailgun", action="store_true", dest="nailgun", default=False, help="Run PRISM in Nailgun mode")
+parser.add_option("--ngprism", dest="ngprism", metavar="FILE", default="ngprism", help="Specify the location of ngprism (for Nailgun mode)")
 parser.add_option("--test-all", action="store_true", dest="testAll", default=False, help="In test mode, don't stop after an error")
 parser.add_option("--no-renaming", action="store_true", dest="noRenaming", default=False, help="Don't rename files to be exported")
 parser.add_option("--debug", action="store_true", dest="debug", default=False, help="Enable debug mode: display debugging info")