diff --git a/src/hb-unicode-private.hh b/src/hb-unicode-private.hh
index cd54cf7e7..ba193e8fa 100644
--- a/src/hb-unicode-private.hh
+++ b/src/hb-unicode-private.hh
@@ -134,10 +134,10 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
    * 6.3 is also added manually.  The new Unicode 6.3 bidi formatting
    * characters are encoded in a block that was Default_Ignorable already.
    *
-   * Note: While U+115F and U+1160 are Default_Ignorable, we do NOT want to
-   * hide them, as the way Uniscribe has implemented them is with regular
-   * spacing glyphs, and that's the way fonts are made to work.  As such,
-   * we make exceptions for those two.
+   * Note: While U+115F, U+1160, U+3164 and U+FFA0 are Default_Ignorable,
+   * we do NOT want to hide them, as the way Uniscribe has implemented them
+   * is with regular spacing glyphs, and that's the way fonts are made to work.
+   * As such, we make exceptions for those four.
    *
    * Gathered from:
    * http://unicode.org/cldr/utility/list-unicodeset.jsp?a=[:DI:]&abb=on&ucd=on&esc=on
@@ -159,10 +159,10 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
    * 200B..200F ;RIGHT-TO-LEFT MARK
    * 202A..202E ;RIGHT-TO-LEFT OVERRIDE
    * 2060..206F ;NOMINAL DIGIT SHAPES
-   * 3164 ;HANGUL FILLER
+   * #3164 ;HANGUL FILLER
    * FE00..FE0F ;VARIATION SELECTOR-16
    * FEFF ;ZERO WIDTH NO-BREAK SPACE
-   * FFA0 ;HALFWIDTH HANGUL FILLER
+   * #FFA0 ;HALFWIDTH HANGUL FILLER
    * FFF0..FFF8 ;<unassigned-FFF8>
    * 1D173..1D17A ;MUSICAL SYMBOL END PHRASE
    * E0000..E0FFF ;<unassigned-E0FFF>
@@ -184,9 +184,8 @@ HB_UNICODE_FUNCS_IMPLEMENT_CALLBACKS_SIMPLE
 	case 0x20: return hb_in_ranges<hb_codepoint_t> (ch, 0x200B, 0x200F,
 							    0x202A, 0x202E,
 							    0x2060, 0x206F);
-	case 0x31: return unlikely (ch == 0x3164);
 	case 0xFE: return hb_in_range<hb_codepoint_t> (ch, 0xFE00, 0xFE0F) || ch == 0xFEFF;
-	case 0xFF: return hb_in_range<hb_codepoint_t> (ch, 0xFFF0, 0xFFF8) || ch == 0xFFA0;
+	case 0xFF: return hb_in_range<hb_codepoint_t> (ch, 0xFFF0, 0xFFF8);
 	default: return false;
       }
     }