diff --git a/panda/src/display/Sources.pp b/panda/src/display/Sources.pp
index 1ffade8890..d4bbf86775 100644
--- a/panda/src/display/Sources.pp
+++ b/panda/src/display/Sources.pp
@@ -69,7 +69,7 @@
     graphicsThreadingModel.cxx \
     graphicsWindow.cxx graphicsWindowInputDevice.cxx  \
     graphicsWindowProc.cxx \
-    graphicsWindowProcCalbackData.cxx \
+    graphicsWindowProcCallbackData.cxx \
     graphicsDevice.cxx \
     lru.cxx \
     nativeWindowHandle.cxx \