diff --git a/src/ecmascript/spidermonkey/form.c b/src/ecmascript/spidermonkey/form.c
index feea2a0d1..49686f1d5 100644
--- a/src/ecmascript/spidermonkey/form.c
+++ b/src/ecmascript/spidermonkey/form.c
@@ -54,7 +54,7 @@ static JSBool input_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval
 
 static const JSClass input_class = {
 	"input", /* here, we unleash ourselves */
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct form_state * */
 	JS_PropertyStub, JS_PropertyStub,
 	input_get_property, input_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
@@ -572,7 +572,7 @@ static JSBool form_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval *
 
 static const JSClass form_class = {
 	"form",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct form_view * */
 	JS_PropertyStub, JS_PropertyStub,
 	form_get_property, form_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
diff --git a/src/ecmascript/spidermonkey/unibar.c b/src/ecmascript/spidermonkey/unibar.c
index a2aef1eaa..4dec02064 100644
--- a/src/ecmascript/spidermonkey/unibar.c
+++ b/src/ecmascript/spidermonkey/unibar.c
@@ -49,14 +49,14 @@ static JSBool unibar_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval
 
 const JSClass menubar_class = {
 	"menubar",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* const char * "t" */
 	JS_PropertyStub, JS_PropertyStub,
 	unibar_get_property, unibar_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
 };
 const JSClass statusbar_class = {
 	"statusbar",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* const char * "s" */
 	JS_PropertyStub, JS_PropertyStub,
 	unibar_get_property, unibar_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
diff --git a/src/ecmascript/spidermonkey/window.c b/src/ecmascript/spidermonkey/window.c
index ad0017c1a..41779b003 100644
--- a/src/ecmascript/spidermonkey/window.c
+++ b/src/ecmascript/spidermonkey/window.c
@@ -49,7 +49,7 @@ static JSBool window_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval
 
 const JSClass window_class = {
 	"window",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct view_state * */
 	JS_PropertyStub, JS_PropertyStub,
 	window_get_property, window_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub
diff --git a/src/scripting/smjs/bookmarks.c b/src/scripting/smjs/bookmarks.c
index 49eda4175..015b42ce3 100644
--- a/src/scripting/smjs/bookmarks.c
+++ b/src/scripting/smjs/bookmarks.c
@@ -133,7 +133,7 @@ bookmark_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
 
 static const JSClass bookmark_class = {
 	"bookmark",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct bookmark * */
 	JS_PropertyStub, JS_PropertyStub,
 	bookmark_get_property, bookmark_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, bookmark_finalize,
@@ -186,7 +186,7 @@ bookmark_folder_get_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
 
 static const JSClass bookmark_folder_class = {
 	"bookmark_folder",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct bookmark * */
 	JS_PropertyStub, JS_PropertyStub,
 	bookmark_folder_get_property, JS_PropertyStub,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, bookmark_finalize,
diff --git a/src/scripting/smjs/cache_object.c b/src/scripting/smjs/cache_object.c
index 3c69788c4..5ef0eb4b0 100644
--- a/src/scripting/smjs/cache_object.c
+++ b/src/scripting/smjs/cache_object.c
@@ -141,7 +141,7 @@ cache_entry_finalize(JSContext *ctx, JSObject *obj)
 	
 static const JSClass cache_entry_class = {
 	"cache_entry",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct cache_entry * */
 	JS_PropertyStub, JS_PropertyStub,
 	cache_entry_get_property, cache_entry_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, cache_entry_finalize
diff --git a/src/scripting/smjs/keybinding.c b/src/scripting/smjs/keybinding.c
index 54541ab50..d5f02e871 100644
--- a/src/scripting/smjs/keybinding.c
+++ b/src/scripting/smjs/keybinding.c
@@ -137,7 +137,7 @@ keymap_finalize(JSContext *ctx, JSObject *obj)
 
 static const JSClass keymap_class = {
 	"keymap",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* int * */
 	JS_PropertyStub, JS_PropertyStub,
 	keymap_get_property, keymap_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, keymap_finalize,
diff --git a/src/scripting/smjs/view_state_object.c b/src/scripting/smjs/view_state_object.c
index a40457e76..0503ec811 100644
--- a/src/scripting/smjs/view_state_object.c
+++ b/src/scripting/smjs/view_state_object.c
@@ -79,7 +79,7 @@ view_state_set_property(JSContext *ctx, JSObject *obj, jsval id, jsval *vp)
 
 static const JSClass view_state_class = {
 	"view_state",
-	JSCLASS_HAS_PRIVATE,
+	JSCLASS_HAS_PRIVATE,	/* struct view_state * */
 	JS_PropertyStub, JS_PropertyStub,
 	view_state_get_property, view_state_set_property,
 	JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub