diff --git a/makepanda/makepanda.py b/makepanda/makepanda.py
index 6d84848806..6239eec395 100755
--- a/makepanda/makepanda.py
+++ b/makepanda/makepanda.py
@@ -3154,6 +3154,8 @@ if (RUNTIME):
   TargetAdd('plugin_plugin.obj', opts=OPTS, input='p3d_plugin_composite1.cxx')
   TargetAdd('plugin_mkdir_complete.obj', opts=OPTS, input='mkdir_complete.cxx')
   TargetAdd('plugin_find_root_dir.obj', opts=OPTS, input='find_root_dir.cxx')
+  if (sys.platform == "darwin"):
+    TargetAdd('plugin_find_root_dir_assist.obj', opts=OPTS, input='find_root_dir_assist.mm')
   TargetAdd('plugin_binaryXml.obj', opts=OPTS, input='binaryXml.cxx')
   TargetAdd('plugin_fileSpec.obj', opts=OPTS, input='fileSpec.cxx')
   TargetAdd('plugin_handleStream.obj', opts=OPTS, input='handleStream.cxx')
@@ -3161,6 +3163,8 @@ if (RUNTIME):
   TargetAdd('p3d_plugin.dll', input='plugin_plugin.obj')
   TargetAdd('p3d_plugin.dll', input='plugin_mkdir_complete.obj')
   TargetAdd('p3d_plugin.dll', input='plugin_find_root_dir.obj')
+  if (sys.platform == "darwin"):
+    TargetAdd('p3d_plugin.dll', input='plugin_find_root_dir_assist.obj')
   TargetAdd('p3d_plugin.dll', input='plugin_fileSpec.obj')
   TargetAdd('p3d_plugin.dll', input='plugin_binaryXml.obj')
   TargetAdd('p3d_plugin.dll', input='plugin_handleStream.obj')