diff --git a/samples/s2_sample_mm/AMBuildScript b/samples/s2_sample_mm/AMBuildScript
index 3f52857..eb105ed 100644
--- a/samples/s2_sample_mm/AMBuildScript
+++ b/samples/s2_sample_mm/AMBuildScript
@@ -52,7 +52,11 @@ def ResolveMMSRoot():
 
 mms_root = ResolveMMSRoot()
 
-SdkHelpers = builder.Eval('hl2sdk-manifests/SdkHelpers.ambuild', {
+if not builder.options.hl2sdk_manifests:
+  raise Exception('Could not find a source copy of HL2SDK manifests')
+hl2sdk_manifests = builder.options.hl2sdk_manifests
+
+SdkHelpers = builder.Eval(os.path.join(hl2sdk_manifests, 'SdkHelpers.ambuild'), {
   'Project': 'metamod'
 })
 
diff --git a/samples/s2_sample_mm/configure.py b/samples/s2_sample_mm/configure.py
index 2ca9277..0605213 100644
--- a/samples/s2_sample_mm/configure.py
+++ b/samples/s2_sample_mm/configure.py
@@ -25,6 +25,8 @@ parser.options.add_argument('-a', '--plugin-alias', type=str, dest='plugin_alias
                        help='Plugin alias')
 parser.options.add_argument('--hl2sdk-root', type=str, dest='hl2sdk_root', default=None,
                        help='Root search folder for HL2SDKs')
+parser.options.add_argument('--hl2sdk-manifests', type=str, dest='hl2sdk_manifests', default=None,
+                       help='HL2SDK manifests source tree folder')
 parser.options.add_argument('--mms_path', type=str, dest='mms_path', default=None,
                        help='Metamod:Source source tree folder')
 parser.options.add_argument('--enable-debug', action='store_const', const='1', dest='debug',