diff --git a/src/dispextern.h b/src/dispextern.h
index 1060895d0f4..9c193e79fd1 100644
--- a/src/dispextern.h
+++ b/src/dispextern.h
@@ -3958,7 +3958,7 @@ void combine_updates (Lisp_Object root_frames);
 void combine_updates_for_frame (struct frame *f, bool inhibit_id_p);
 void tty_raise_lower_frame (struct frame *f, bool raise);
 int max_child_z_order (struct frame *parent);
-void frame_pos_abs (struct frame *f, int *x, int *y);
+void root_xy (struct frame *f, int x, int y, int *rx, int *ry);
 bool is_frame_ancestor (struct frame *f1, struct frame *f2);
 
 INLINE_HEADER_END
diff --git a/src/dispnew.c b/src/dispnew.c
index 724ec6ece9a..00e59c767e8 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -3313,16 +3313,18 @@ rect_intersect (struct rect *r, struct rect r1, struct rect r2)
   return true;
 }
 
-/* Return the absolute position of frame F in *X and *Y.  */
+/* Translate (X, Y) relative to frame F to absolute coordinates
+   in (*X, *Y).  */
 
 void
-frame_pos_abs (struct frame *f, int *x, int *y)
+root_xy (struct frame *f, int x, int y, int *rx, int *ry)
 {
-  *x = *y = 0;
+  *rx = x;
+  *ry = y;
   for (; f; f = FRAME_PARENT_FRAME (f))
     {
-      *x += f->left_pos;
-      *y += f->top_pos;
+      *rx += f->left_pos;
+      *ry += f->top_pos;
     }
 }
 
@@ -3333,7 +3335,7 @@ static struct rect
 frame_rect_abs (struct frame *f)
 {
   int x, y;
-  frame_pos_abs (f, &x, &y);
+  root_xy (f, 0, 0, &x, &y);
   return (struct rect) { x, y, f->total_cols, f->total_lines };
 }
 
@@ -3875,10 +3877,7 @@ abs_cursor_pos (struct frame *f, int *x, int *y)
 
       wx += max (0, w->left_margin_cols);
 
-      int fx, fy;
-      frame_pos_abs (f, &fx, &fy);
-      *x = fx + wx;
-      *y = fy + wy;
+      root_xy (f, wx, wy, x, y);
       return true;
     }
 
diff --git a/src/term.c b/src/term.c
index 4ae9c373888..00bc94e6e31 100644
--- a/src/term.c
+++ b/src/term.c
@@ -2996,10 +2996,9 @@ mouse_get_xy (int *x, int *y)
   struct frame *sf = SELECTED_FRAME ();
   if (f == sf || is_frame_ancestor (sf, f))
     {
-      int fx, fy;
-      frame_pos_abs (f, &fx, &fy);
-      *x = fx + XFIXNUM (XCAR (XCDR (mouse)));
-      *y = fy + XFIXNUM (XCDR (XCDR (mouse)));
+      int mx = XFIXNUM (XCAR (XCDR (mouse)));
+      int my = XFIXNUM (XCDR (XCDR (mouse)));
+      root_xy (f, mx, my, x, y);
     }
 }