diff --git a/cogl-debug.h b/cogl-debug.h
index 44711c172..7440831b9 100644
--- a/cogl-debug.h
+++ b/cogl-debug.h
@@ -6,13 +6,14 @@
 G_BEGIN_DECLS
 
 typedef enum {
-  COGL_DEBUG_MISC      = 1 << 0,
-  COGL_DEBUG_TEXTURE   = 1 << 1,
-  COGL_DEBUG_MATERIAL  = 1 << 2,
-  COGL_DEBUG_SHADER    = 1 << 3,
-  COGL_DEBUG_OFFSCREEN = 1 << 4,
-  COGL_DEBUG_DRAW      = 1 << 5,
-  COGL_DEBUG_PANGO     = 1 << 6
+  COGL_DEBUG_MISC       = 1 << 0,
+  COGL_DEBUG_TEXTURE    = 1 << 1,
+  COGL_DEBUG_MATERIAL   = 1 << 2,
+  COGL_DEBUG_SHADER     = 1 << 3,
+  COGL_DEBUG_OFFSCREEN  = 1 << 4,
+  COGL_DEBUG_DRAW       = 1 << 5,
+  COGL_DEBUG_PANGO      = 1 << 6,
+  COGL_DEBUG_RECTANGLES = 1 << 7
 } CoglDebugFlags;
 
 #ifdef COGL_ENABLE_DEBUG
diff --git a/common/cogl-debug.c b/common/cogl-debug.c
index 0497d744f..2200b1f19 100644
--- a/common/cogl-debug.c
+++ b/common/cogl-debug.c
@@ -14,7 +14,8 @@ static const GDebugKey cogl_debug_keys[] = {
   { "shader", COGL_DEBUG_SHADER },
   { "offscreen", COGL_DEBUG_OFFSCREEN },
   { "draw", COGL_DEBUG_DRAW },
-  { "pango", COGL_DEBUG_PANGO }
+  { "pango", COGL_DEBUG_PANGO },
+  { "rectangles", COGL_DEBUG_RECTANGLES }
 };
 
 static const gint n_cogl_debug_keys = G_N_ELEMENTS (cogl_debug_keys);
diff --git a/common/cogl-primitives.c b/common/cogl-primitives.c
index 881e6cef4..a1b0e2bc2 100644
--- a/common/cogl-primitives.c
+++ b/common/cogl-primitives.c
@@ -160,11 +160,11 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
 
 
   /* DEBUGGING CODE XXX:
-   * Uncommenting this will cause all rectangles to be drawn with a red, green
+   * This path will cause all rectangles to be drawn with a red, green
    * or blue outline with no blending. This may e.g. help with debugging
    * texture slicing issues or blending issues, plus it looks quite cool.
    */
-#if 0
+  if (cogl_debug_flags & COGL_DEBUG_RECTANGLES)
     {
       static CoglHandle outline = COGL_INVALID_HANDLE;
       static int color = 0;
@@ -172,7 +172,7 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
         outline = cogl_material_new ();
 
       cogl_enable (COGL_ENABLE_VERTEX_ARRAY);
-      for (i = 0; i < batch_len; i++, color = (++color) % 3)
+      for (i = 0; i < batch_len; i++, color = (color + 1) % 3)
         {
           cogl_material_set_color4ub (outline,
                                       color == 0 ? 0xff : 0x00,
@@ -184,7 +184,6 @@ _cogl_journal_flush_quad_batch (CoglJournalEntry *batch_start,
           GE( glDrawArrays (GL_LINE_LOOP, 4 * i, 4) );
         }
     }
-#endif
 }
 
 void