diff --git a/source/blender/makesrna/intern/rna_wm.c b/source/blender/makesrna/intern/rna_wm.c
index de872b41335..10e27814236 100644
--- a/source/blender/makesrna/intern/rna_wm.c
+++ b/source/blender/makesrna/intern/rna_wm.c
@@ -255,6 +255,8 @@ EnumPropertyItem keymap_modifiers_items[] = {
 
 #include "BKE_idprop.h"
 
+#include "MEM_guardedalloc.h"
+
 static wmOperator *rna_OperatorProperties_find_operator(PointerRNA *ptr)
 {
 	wmWindowManager *wm= ptr->id.data;
@@ -558,6 +560,8 @@ static void rna_wmKeyMapItem_idname_set(PointerRNA *ptr, const char *value)
 
 	WM_operator_bl_idname(idname, value);
 	BLI_strncpy(kmi->idname, idname, sizeof(kmi->idname));
+
+	WM_keymap_properties_reset(kmi);
 }
 
 #else
diff --git a/source/blender/windowmanager/WM_api.h b/source/blender/windowmanager/WM_api.h
index 22820d578a5..a270b75eea1 100644
--- a/source/blender/windowmanager/WM_api.h
+++ b/source/blender/windowmanager/WM_api.h
@@ -112,6 +112,7 @@ wmKeyMap	*WM_keymap_active(struct wmWindowManager *wm, struct wmKeyMap *keymap);
 int			 WM_keymap_user_init(struct wmWindowManager *wm, struct wmKeyMap *keymap);
 wmKeyMap	*WM_keymap_copy_to_user(struct wmKeyMap *keymap);
 void		WM_keymap_restore_to_default(struct wmKeyMap *keymap);
+void		WM_keymap_properties_reset(struct wmKeyMapItem *kmi);
 
 wmKeyMap	*WM_modalkeymap_add(struct wmKeyConfig *keyconf, char *idname, struct EnumPropertyItem *items);
 wmKeyMap	*WM_modalkeymap_get(struct wmKeyConfig *keyconf, char *idname);
diff --git a/source/blender/windowmanager/intern/wm_keymap.c b/source/blender/windowmanager/intern/wm_keymap.c
index b3269a23277..b22f01b7d7a 100644
--- a/source/blender/windowmanager/intern/wm_keymap.c
+++ b/source/blender/windowmanager/intern/wm_keymap.c
@@ -55,6 +55,17 @@
 
 /* ********************* key config ***********************/
 
+void WM_keymap_properties_reset(wmKeyMapItem *kmi)
+{
+	WM_operator_properties_free(kmi->ptr);
+	MEM_freeN(kmi->ptr);
+
+	kmi->ptr = NULL;
+	kmi->properties = NULL;
+
+	WM_operator_properties_alloc(&(kmi->ptr), &(kmi->properties), kmi->idname);
+}
+
 static void keymap_properties_set(wmKeyMapItem *kmi)
 {
 	WM_operator_properties_alloc(&(kmi->ptr), &(kmi->properties), kmi->idname);