diff --git a/source/blender/editors/animation/anim_channels_edit.c b/source/blender/editors/animation/anim_channels_edit.c
index a7c37d371e5..8ac7406462d 100644
--- a/source/blender/editors/animation/anim_channels_edit.c
+++ b/source/blender/editors/animation/anim_channels_edit.c
@@ -1529,7 +1529,7 @@ static int animchannels_setflag_exec(bContext *C, wmOperator *op)
 	return OPERATOR_FINISHED;
 }
 
-
+/* duplicate of 'ANIM_OT_channels_setting_toggle' for menu title only, weak! */
 static void ANIM_OT_channels_setting_enable (wmOperatorType *ot)
 {
 	/* identifiers */
@@ -1551,7 +1551,7 @@ static void ANIM_OT_channels_setting_enable (wmOperatorType *ot)
 		/* setting to set */
 	ot->prop= RNA_def_enum(ot->srna, "type", prop_animchannel_settings_types, 0, "Type", "");
 }
-
+/* duplicate of 'ANIM_OT_channels_setting_toggle' for menu title only, weak! */
 static void ANIM_OT_channels_setting_disable (wmOperatorType *ot)
 {
 	/* identifiers */
@@ -1574,28 +1574,6 @@ static void ANIM_OT_channels_setting_disable (wmOperatorType *ot)
 	ot->prop= RNA_def_enum(ot->srna, "type", prop_animchannel_settings_types, 0, "Type", "");
 }
 
-static void ANIM_OT_channels_setting_invert (wmOperatorType *ot)
-{
-	/* identifiers */
-	ot->name= "Invert Channel Setting";
-	ot->idname= "ANIM_OT_channels_setting_toggle";
-	ot->description= "Invert specified setting on all selected animation channels";
-	
-	/* api callbacks */
-	ot->invoke= WM_menu_invoke;
-	ot->exec= animchannels_setflag_exec;
-	ot->poll= animedit_poll_channels_active;
-	
-	/* flags */
-	ot->flag= OPTYPE_REGISTER|OPTYPE_UNDO;
-	
-	/* props */
-		/* flag-setting mode */
-	RNA_def_enum(ot->srna, "mode", prop_animchannel_setflag_types, ACHANNEL_SETFLAG_INVERT, "Mode", "");
-		/* setting to set */
-	ot->prop= RNA_def_enum(ot->srna, "type", prop_animchannel_settings_types, 0, "Type", "");
-}
-
 static void ANIM_OT_channels_setting_toggle (wmOperatorType *ot)
 {
 	/* identifiers */
@@ -2401,7 +2379,6 @@ void ED_operatortypes_animchannels(void)
 	
 	WM_operatortype_append(ANIM_OT_channels_setting_enable);
 	WM_operatortype_append(ANIM_OT_channels_setting_disable);
-	WM_operatortype_append(ANIM_OT_channels_setting_invert);
 	WM_operatortype_append(ANIM_OT_channels_setting_toggle);
 	
 	WM_operatortype_append(ANIM_OT_channels_delete);
diff --git a/source/tests/bl_run_operators.py b/source/tests/bl_run_operators.py
index b64055df252..476ccc30b54 100644
--- a/source/tests/bl_run_operators.py
+++ b/source/tests/bl_run_operators.py
@@ -137,7 +137,25 @@ def ctx_weightpaint():
     bpy.ops.object.mode_set(mode='WEIGHT_PAINT')
 
 
+def bpy_check_type_duplicates():
+    # non essential sanity check
+    bl_types = dir(bpy.types)
+    bl_types_unique = set(bl_types)
+    
+    if len(bl_types) != len(bl_types_unique):
+        print("Error, found duplicates in 'bpy.types'")
+        for t in sorted(bl_types_unique):
+            tot = bl_types.count(t)
+            if tot > 1:
+                print("    '%s', %d" % (t, tot))
+        import sys
+        sys.exit(1)
+
+
 def main():
+
+    bpy_check_type_duplicates()
+
     # bpy.ops.wm.read_factory_settings()
     import bpy
     operators = []