diff --git a/panda/src/distort/Sources.pp b/panda/src/distort/Sources.pp
index 7858716e19..7af9977e1d 100644
--- a/panda/src/distort/Sources.pp
+++ b/panda/src/distort/Sources.pp
@@ -5,14 +5,19 @@
   #define TARGET distort
   #define LOCAL_LIBS \
     sgraphutil sgraph sgattrib gobj linmath
+    
+  #define COMBINED_SOURCES $[TARGET]_composite1.cxx
 
-  #define SOURCES \
-    config_distort.cxx config_distort.h \
-    cylindricalLens.cxx cylindricalLens.h cylindricalLens.I \
-    fisheyeLens.cxx fisheyeLens.h fisheyeLens.I \
-    nonlinearImager.cxx nonlinearImager.h nonlinearImager.I \
-    pSphereLens.cxx pSphereLens.h pSphereLens.I \
-    projectionScreen.cxx projectionScreen.h projectionScreen.I
+  #define SOURCES config_distort.h \
+    projectionScreen.h projectionScreen.I \
+    cylindricalLens.h cylindricalLens.I \
+    fisheyeLens.h fisheyeLens.I \
+    nonlinearImager.h nonlinearImager.I \
+    pSphereLens.h pSphereLens.I
+
+  #define INCLUDED_SOURCES \
+    config_distort.cxx cylindricalLens.cxx fisheyeLens.cxx nonlinearImager.cxx \
+    projectionScreen.cxx pSphereLens.cxx 
 
   #define INSTALL_HEADERS