diff --git a/dtool/pptempl/Template.gmsvc.pp b/dtool/pptempl/Template.gmsvc.pp
index b8799e27c9..78f3bdd0da 100644
--- a/dtool/pptempl/Template.gmsvc.pp
+++ b/dtool/pptempl/Template.gmsvc.pp
@@ -207,6 +207,7 @@ clean :
 #if $[st_sources]
 	rm -rf $[st_dir]
 #endif
+	rm -f *.pyc *.pyo  // Also scrub out old generated Python code.
 
 // 'cleanall' is not much more thorough than 'clean': At the moment,
 // it also cleans up the bison and flex output, as well as the
diff --git a/dtool/pptempl/Template.msvc.pp b/dtool/pptempl/Template.msvc.pp
index 40cb5c62ef..c0abb1e022 100644
--- a/dtool/pptempl/Template.msvc.pp
+++ b/dtool/pptempl/Template.msvc.pp
@@ -204,6 +204,7 @@ clean :
 #if $[st_sources]
 	-rmdir /s /q $[st_dir]
 #endif
+	-del /f *.pyc *.pyo  // Also scrub out old generated Python code.
 
 // 'cleanall' is not much more thorough than 'clean': At the moment,
 // it also cleans up the bison and flex output, as well as the
diff --git a/dtool/pptempl/Template.unix.pp b/dtool/pptempl/Template.unix.pp
index c3bf31fa39..db26bbfe77 100644
--- a/dtool/pptempl/Template.unix.pp
+++ b/dtool/pptempl/Template.unix.pp
@@ -166,6 +166,7 @@ clean :
 #if $[st_sources]
 	rm -rf $[st_dir]
 #endif
+	rm -f *.pyc *.pyo  // Also scrub out old generated Python code.
 
 // 'cleanall' is not much more thorough than 'clean': At the moment,
 // it also cleans up the bison and flex output, as well as the