diff --git a/src/hb-face-private.hh b/src/hb-face-private.hh
index eb0e850aa..72f08a599 100644
--- a/src/hb-face-private.hh
+++ b/src/hb-face-private.hh
@@ -55,10 +55,10 @@ struct hb_face_t {
   mutable unsigned int num_glyphs;	/* Number of glyphs. */
 
   enum dirty_t {
-    NOTHING	= 0x0000,
-    INDEX	= 0x0001,
-    UPEM	= 0x0002,
-    NUM_GLYPHS	= 0x0004,
+    DIRTY_NOTHING	= 0x0000,
+    DIRTY_INDEX		= 0x0001,
+    DIRTY_UPEM		= 0x0002,
+    DIRTY_NUM_GLYPHS	= 0x0004,
   } dirty;
 
   struct hb_shaper_data_t shaper_data;	/* Various shaper data. */
diff --git a/src/hb-face.cc b/src/hb-face.cc
index 1800c995a..22998f005 100644
--- a/src/hb-face.cc
+++ b/src/hb-face.cc
@@ -51,7 +51,7 @@ const hb_face_t _hb_face_nil = {
   1000, /* upem */
   0,    /* num_glyphs */
 
-  hb_face_t::NOTHING, /* dirty */
+  hb_face_t::DIRTY_NOTHING, /* dirty */
 
   {
 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
@@ -370,7 +370,7 @@ hb_face_set_index (hb_face_t    *face,
   if (face->index == index)
     return;
 
-  face->dirty |= face->INDEX;
+  face->dirty |= face->DIRTY_INDEX;
 
   face->index = index;
 }
@@ -410,7 +410,7 @@ hb_face_set_upem (hb_face_t    *face,
   if (face->upem == upem)
     return;
 
-  face->dirty |= face->UPEM;
+  face->dirty |= face->DIRTY_UPEM;
 
   face->upem = upem;
 }
@@ -459,7 +459,7 @@ hb_face_set_glyph_count (hb_face_t    *face,
   if (face->num_glyphs == glyph_count)
     return;
 
-  face->dirty |= face->NUM_GLYPHS;
+  face->dirty |= face->DIRTY_NUM_GLYPHS;
 
   face->num_glyphs = glyph_count;
 }
diff --git a/src/hb-font-private.hh b/src/hb-font-private.hh
index fbb16a0b7..ed9f2c54a 100644
--- a/src/hb-font-private.hh
+++ b/src/hb-font-private.hh
@@ -117,13 +117,13 @@ struct hb_font_t {
   hb_destroy_func_t  destroy;
 
   enum dirty_t {
-    NOTHING	= 0x0000,
-    FACE	= 0x0001,
-    PARENT	= 0x0002,
-    FUNCS	= 0x0004,
-    SCALE	= 0x0008,
-    PPEM	= 0x0010,
-    VARIATIONS	= 0x0020,
+    DIRTY_NOTHING	= 0x0000,
+    DIRTY_FACE		= 0x0001,
+    DIRTY_PARENT	= 0x0002,
+    DIRTY_FUNCS		= 0x0004,
+    DIRTY_SCALE		= 0x0008,
+    DIRTY_PPEM		= 0x0010,
+    DIRTY_VARIATIONS	= 0x0020,
   } dirty;
 
   struct hb_shaper_data_t shaper_data;
diff --git a/src/hb-font.cc b/src/hb-font.cc
index e900bd3f6..a684c234d 100644
--- a/src/hb-font.cc
+++ b/src/hb-font.cc
@@ -1196,7 +1196,7 @@ hb_font_get_empty (void)
     NULL, /* user_data */
     NULL, /* destroy */
 
-    hb_font_t::NOTHING, /* dirty */
+    hb_font_t::DIRTY_NOTHING, /* dirty */
 
     {
 #define HB_SHAPER_IMPLEMENT(shaper) HB_SHAPER_DATA_INVALID,
@@ -1353,7 +1353,7 @@ hb_font_set_parent (hb_font_t *font,
   if (parent == font->parent)
     return;
 
-  font->dirty |= font->PARENT;
+  font->dirty |= font->DIRTY_PARENT;
 
   hb_font_t *old = font->parent;
 
@@ -1400,7 +1400,7 @@ hb_font_set_face (hb_font_t *font,
   if (font->face == face)
     return;
 
-  font->dirty |= font->FACE;
+  font->dirty |= font->DIRTY_FACE;
 
   hb_face_t *old = font->face;
 
@@ -1455,7 +1455,7 @@ hb_font_set_funcs (hb_font_t         *font,
   if (!klass)
     klass = hb_font_funcs_get_empty ();
 
-  font->dirty |= font->FUNCS;
+  font->dirty |= font->DIRTY_FUNCS;
 
   hb_font_funcs_reference (klass);
   hb_font_funcs_destroy (font->klass);
@@ -1515,7 +1515,7 @@ hb_font_set_scale (hb_font_t *font,
   if (font->x_scale == x_scale && font->y_scale == y_scale)
     return;
 
-  font->dirty |= font->SCALE;
+  font->dirty |= font->DIRTY_SCALE;
 
   font->x_scale = x_scale;
   font->y_scale = y_scale;
@@ -1561,7 +1561,7 @@ hb_font_set_ppem (hb_font_t *font,
   if (font->x_ppem == x_ppem && font->y_ppem == y_ppem)
     return;
 
-  font->dirty |= font->PPEM;
+  font->dirty |= font->DIRTY_PPEM;
 
   font->x_ppem = x_ppem;
   font->y_ppem = y_ppem;
@@ -1603,7 +1603,7 @@ _hb_font_adopt_var_coords_normalized (hb_font_t *font,
     return;
   }
 
-  font->dirty |= font->VARIATIONS;
+  font->dirty |= font->DIRTY_VARIATIONS;
 
   free (font->coords);