diff --git a/ChangeLog b/ChangeLog
index d9e55724a..7f450b857 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2018-07-24  Hin-Tak Leung  <htl10@users.sourceforge.net>
+
+	[truetype] Match ttdebug's naming of instruction mnemonics.
+
+	* src/truetype/ttinterp.c: The form used in ttdebug,
+	"MDRP[G,B,W,?]", etc., is slightly more readable than
+	"MDRP[00,01,02,03]".
+
 2018-07-24  Werner Lemberg  <wl@gnu.org>
 
 	* src/pcf/pcfread.c (pcf_get_encodings): Thinko.
diff --git a/src/truetype/ttinterp.c b/src/truetype/ttinterp.c
index da45c373a..154c8cbd0 100644
--- a/src/truetype/ttinterp.c
+++ b/src/truetype/ttinterp.c
@@ -1154,73 +1154,73 @@
     "8 PushW[6]",
     "8 PushW[7]",
 
-    "8 MDRP[00]",
-    "8 MDRP[01]",
-    "8 MDRP[02]",
-    "8 MDRP[03]",
-    "8 MDRP[04]",
-    "8 MDRP[05]",
-    "8 MDRP[06]",
-    "8 MDRP[07]",
-    "8 MDRP[08]",
-    "8 MDRP[09]",
-    "8 MDRP[10]",
-    "8 MDRP[11]",
-    "8 MDRP[12]",
-    "8 MDRP[13]",
-    "8 MDRP[14]",
-    "8 MDRP[15]",
+    "7 MDRP[G]",
+    "7 MDRP[B]",
+    "7 MDRP[W]",
+    "7 MDRP[?]",
+    "8 MDRP[rG]",
+    "8 MDRP[rB]",
+    "8 MDRP[rW]",
+    "8 MDRP[r?]",
+    "8 MDRP[mG]",
+    "8 MDRP[mB]",
+    "8 MDRP[mW]",
+    "8 MDRP[m?]",
+    "9 MDRP[mrG]",
+    "9 MDRP[mrB]",
+    "9 MDRP[mrW]",
+    "9 MDRP[mr?]",
 
-    "8 MDRP[16]",
-    "8 MDRP[17]",
-    "8 MDRP[18]",
-    "8 MDRP[19]",
-    "8 MDRP[20]",
-    "8 MDRP[21]",
-    "8 MDRP[22]",
-    "8 MDRP[23]",
-    "8 MDRP[24]",
-    "8 MDRP[25]",
-    "8 MDRP[26]",
-    "8 MDRP[27]",
-    "8 MDRP[28]",
-    "8 MDRP[29]",
-    "8 MDRP[30]",
-    "8 MDRP[31]",
+    "7 MDRP[pG]",
+    "7 MDRP[pB]",
+    "7 MDRP[pW]",
+    "7 MDRP[p?]",
+    "8 MDRP[prG]",
+    "8 MDRP[prB]",
+    "8 MDRP[prW]",
+    "8 MDRP[pr?]",
+    "8 MDRP[pmG]",
+    "8 MDRP[pmB]",
+    "8 MDRP[pmW]",
+    "8 MDRP[pm?]",
+    "9 MDRP[pmrG]",
+    "9 MDRP[pmrB]",
+    "9 MDRP[pmrW]",
+    "9 MDRP[pmr?]",
 
-    "8 MIRP[00]",
-    "8 MIRP[01]",
-    "8 MIRP[02]",
-    "8 MIRP[03]",
-    "8 MIRP[04]",
-    "8 MIRP[05]",
-    "8 MIRP[06]",
-    "8 MIRP[07]",
-    "8 MIRP[08]",
-    "8 MIRP[09]",
-    "8 MIRP[10]",
-    "8 MIRP[11]",
-    "8 MIRP[12]",
-    "8 MIRP[13]",
-    "8 MIRP[14]",
-    "8 MIRP[15]",
+    "7 MIRP[G]",
+    "7 MIRP[B]",
+    "7 MIRP[W]",
+    "7 MIRP[?]",
+    "8 MIRP[rG]",
+    "8 MIRP[rB]",
+    "8 MIRP[rW]",
+    "8 MIRP[r?]",
+    "8 MIRP[mG]",
+    "8 MIRP[mB]",
+    "8 MIRP[mW]",
+    "8 MIRP[m?]",
+    "9 MIRP[mrG]",
+    "9 MIRP[mrB]",
+    "9 MIRP[mrW]",
+    "9 MIRP[mr?]",
 
-    "8 MIRP[16]",
-    "8 MIRP[17]",
-    "8 MIRP[18]",
-    "8 MIRP[19]",
-    "8 MIRP[20]",
-    "8 MIRP[21]",
-    "8 MIRP[22]",
-    "8 MIRP[23]",
-    "8 MIRP[24]",
-    "8 MIRP[25]",
-    "8 MIRP[26]",
-    "8 MIRP[27]",
-    "8 MIRP[28]",
-    "8 MIRP[29]",
-    "8 MIRP[30]",
-    "8 MIRP[31]"
+    "7 MIRP[pG]",
+    "7 MIRP[pB]",
+    "7 MIRP[pW]",
+    "7 MIRP[p?]",
+    "8 MIRP[prG]",
+    "8 MIRP[prB]",
+    "8 MIRP[prW]",
+    "8 MIRP[pr?]",
+    "8 MIRP[pmG]",
+    "8 MIRP[pmB]",
+    "8 MIRP[pmW]",
+    "8 MIRP[pm?]",
+    "9 MIRP[pmrG]",
+    "9 MIRP[pmrB]",
+    "9 MIRP[pmrW]",
+    "9 MIRP[pmr?]"
   };
 
 #endif /* FT_DEBUG_LEVEL_TRACE */