diff --git a/src/dispnew.c b/src/dispnew.c
index 7930fa59968..fb313bfd1af 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -500,16 +500,15 @@ adjust_glyph_matrix (struct window *w, struct glyph_matrix *matrix, int x, int y
 
 	  while (row < end)
 	    {
-	      /* Only realloc if matrix got wider or taller (bug#77961).  */
+	      /* Realloc if matrix got wider or taller (bug#77961).  */
 	      if (dim.width > matrix->matrix_w || new_rows)
 		{
-		  row->glyphs[LEFT_MARGIN_AREA]
-		    = xnrealloc (row->glyphs[LEFT_MARGIN_AREA],
-				 dim.width, sizeof (struct glyph));
+		  xfree (row->glyphs[LEFT_MARGIN_AREA]);
+		  row->glyphs[LEFT_MARGIN_AREA] = NULL;
 		  /* We actually need to clear only the 'frame' member, but
 		     it's easier to clear everything.  */
-		  memset (row->glyphs[LEFT_MARGIN_AREA], 0,
-			  dim.width * sizeof (struct glyph));
+		  row->glyphs[LEFT_MARGIN_AREA]
+		    = xcalloc (dim.width, sizeof (struct glyph));
 		}
 
 	      if ((row == matrix->rows + dim.height - 1