diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index e489d43675..008956a8e0 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-15  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR binutils/21594
+	* i386-dis.c (OP_E_register): Check valid bnd register.
+	(OP_G): Likewise.
+
 2017-06-15  Nick Clifton  <nickc@redhat.com>
 
 	PR binutils/21595
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index b35dbc046e..d461d08594 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -15025,6 +15025,11 @@ OP_E_register (int bytemode, int sizeflag)
       names = address_mode == mode_64bit ? names64 : names32;
       break;
     case bnd_mode:
+      if (reg > 0x3)
+	{
+	  oappend ("(bad)");
+	  return;
+	}
       names = names_bnd;
       break;
     case indir_v_mode:
@@ -15569,6 +15574,11 @@ OP_G (int bytemode, int sizeflag)
       oappend (names64[modrm.reg + add]);
       break;
     case bnd_mode:
+      if (modrm.reg > 0x3)
+	{
+	  oappend ("(bad)");
+	  return;
+	}
       oappend (names_bnd[modrm.reg]);
       break;
     case v_mode: