diff --git a/panda/src/pipeline/CMakeLists.txt b/panda/src/pipeline/CMakeLists.txt
index aa7852623b..75e83c9614 100644
--- a/panda/src/pipeline/CMakeLists.txt
+++ b/panda/src/pipeline/CMakeLists.txt
@@ -115,11 +115,9 @@ endif()
 
 set(P3PIPELINE_IGATEEXT
   pmutex_ext.h
-  pmutex_ext.I
   pythonThread.cxx
   pythonThread.h
   reMutex_ext.h
-  reMutex_ext.I
 )
 
 composite_sources(p3pipeline P3PIPELINE_SOURCES)
diff --git a/panda/src/putil/CMakeLists.txt b/panda/src/putil/CMakeLists.txt
index 1332402586..ecc14b9843 100644
--- a/panda/src/putil/CMakeLists.txt
+++ b/panda/src/putil/CMakeLists.txt
@@ -129,20 +129,15 @@ set(P3PUTIL_IGATEEXT
   bamWriter_ext.h
   bitArray_ext.cxx
   bitArray_ext.h
-  bitArray_ext.I
   bitMask_ext.h
-  bitMask_ext.I
   callbackObject_ext.h
   doubleBitMask_ext.h
-  doubleBitMask_ext.I
   paramPyObject.cxx
   paramPyObject.h
-  paramPyObject.I
   pythonCallbackObject.cxx
   pythonCallbackObject.h
   sparseArray_ext.cxx
   sparseArray_ext.h
-  sparseArray_ext.I
   typedWritable_ext.cxx
   typedWritable_ext.h
 )