diff --git a/src/hb-cff-interp-common.hh b/src/hb-cff-interp-common.hh
index 266270cc7..52fc1ee43 100644
--- a/src/hb-cff-interp-common.hh
+++ b/src/hb-cff-interp-common.hh
@@ -603,13 +603,13 @@ struct ArgStack : Stack<ARG, 513>
 
   inline void reverse_range (int i, int j)
   {
-    assert (i >= 0 && i < j);
+    assert (i >= 0 && i <= j);
     ARG  tmp;
     while (i < j)
     {
       tmp = S::elements[i];
       S::elements[i++] = S::elements[j];
-      S::elements[j++] = tmp;
+      S::elements[j--] = tmp;
     }
   }
 
diff --git a/test/api/fonts/cff1_legacyops.otf b/test/api/fonts/cff1_legacyops.otf
new file mode 100644
index 000000000..ca50dab5a
Binary files /dev/null and b/test/api/fonts/cff1_legacyops.otf differ
diff --git a/test/api/test-ot-extents-cff.c b/test/api/test-ot-extents-cff.c
index 607a4d303..244faa8f6 100644
--- a/test/api/test-ot-extents-cff.c
+++ b/test/api/test-ot-extents-cff.c
@@ -52,6 +52,28 @@ test_extents_cff1 (void)
   hb_font_destroy (font);
 }
 
+static void
+test_extents_cff1_legacyops (void)
+{
+  hb_face_t *face = hb_subset_test_open_font ("fonts/cff1_legacyops.otf");
+  g_assert (face);
+  hb_font_t *font = hb_font_create (face);
+  hb_face_destroy (face);
+  g_assert (font);
+  hb_ot_font_set_funcs (font);
+
+  hb_glyph_extents_t  extents;
+  hb_bool_t result = hb_font_get_glyph_extents (font, 0, &extents);
+  g_assert (result);
+
+  g_assert_cmpint (extents.x_bearing, ==, 20);
+  g_assert_cmpint (extents.y_bearing, ==, 800);
+  g_assert_cmpint (extents.width, ==, 160);
+  g_assert_cmpint (extents.height, ==, -810);
+
+  hb_font_destroy (font);
+}
+
 static void
 test_extents_cff2 (void)
 {
@@ -90,6 +112,7 @@ main (int argc, char **argv)
   hb_test_init (&argc, &argv);
 
   hb_test_add (test_extents_cff1);
+  hb_test_add (test_extents_cff1_legacyops);
   hb_test_add (test_extents_cff2);
 
   return hb_test_run ();