diff --git a/include/opcode/ChangeLog b/include/opcode/ChangeLog
index 3c69275d6..e7bfecdec 100644
--- a/include/opcode/ChangeLog
+++ b/include/opcode/ChangeLog
@@ -1,3 +1,9 @@
+2011-07-29  Maciej W. Rozycki  <macro@codesourcery.com>
+
+	* mips.h: Clarify the description of microMIPS instruction
+	manipulation macros.
+	(MICROMIPSOP_MASK_MAJOR, MICROMIPSOP_SH_MAJOR): Remove macros.
+
 2011-07-24  Chao-ying Fu  <fu@mips.com>
             Maciej W. Rozycki  <macro@codesourcery.com>
 
diff --git a/include/opcode/mips.h b/include/opcode/mips.h
index ba68331de..609a4af53 100644
--- a/include/opcode/mips.h
+++ b/include/opcode/mips.h
@@ -1329,13 +1329,10 @@ extern int bfd_mips_num_opcodes;
 extern const struct mips_opcode mips16_opcodes[];
 extern const int bfd_mips16_num_opcodes;
 
-/* These are the bitmasks and shift counts used for the different
-   fields in the instruction formats.  Other than MAJOR, no masks are
-   provided for the fixed portions of an instruction, since they are
-   not needed.  */
+/* These are the bit masks and shift counts used for the different fields
+   in the microMIPS instruction formats.  No masks are provided for the
+   fixed portions of an instruction, since they are not needed.  */
 
-#define MICROMIPSOP_MASK_MAJOR		0x3f
-#define MICROMIPSOP_SH_MAJOR		26
 #define MICROMIPSOP_MASK_IMMEDIATE	0xffff
 #define MICROMIPSOP_SH_IMMEDIATE	0
 #define MICROMIPSOP_MASK_DELTA		0xffff