diff --git a/dtool/src/prc/Sources.pp b/dtool/src/prc/Sources.pp
index cac6f51db1..4a1740b6fd 100644
--- a/dtool/src/prc/Sources.pp
+++ b/dtool/src/prc/Sources.pp
@@ -39,6 +39,9 @@
     streamReader.I streamReader.h \
     streamWrapper.I streamWrapper.h \
     streamWriter.I streamWriter.h
+
+  // A generated file
+  #define SOURCES $[SOURCES] prc_parameters.h 
   
   #define INCLUDED_SOURCES \
     config_prc.cxx \