diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 88f9294fe2..e918abca27 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,8 @@
+2013-05-09  Alan Modra  <amodra@gmail.com>
+
+	* ppc-opc.c (extract_vlesi): Properly sign extend.
+	(extract_vlensi): Likewise.  Comment reason for setting invalid.
+
 2013-05-02  Nick Clifton  <nickc@redhat.com>
 
 	* msp430-dis.c: Add support for MSP430X instructions.
diff --git a/opcodes/ppc-opc.c b/opcodes/ppc-opc.c
index 80dfa24615..62edf02689 100644
--- a/opcodes/ppc-opc.c
+++ b/opcodes/ppc-opc.c
@@ -2022,11 +2022,8 @@ extract_vlesi (unsigned long insn,
              ppc_cpu_t dialect ATTRIBUTE_UNUSED,
              int *invalid ATTRIBUTE_UNUSED)
 {
-  /* RWRW Because I don't know how to make int be 16 and long be 32 */
-  /* I can't rely on casting an int to long to get sign extension. */
   long value = ((insn >> 10) & 0xf800) | (insn & 0x7ff);
-  if (value & 0x8000)
-    value |= 0xffff0000;
+  value = (value ^ 0x8000) - 0x8000;
   return value;
 }
 
@@ -2045,8 +2042,8 @@ extract_vlensi (unsigned long insn,
              int *invalid ATTRIBUTE_UNUSED)
 {
   long value = ((insn >> 10) & 0xf800) | (insn & 0x7ff);
-  if (value & 0x8000)
-    value |= 0xffff0000;
+  value = (value ^ 0x8000) - 0x8000;
+  /* Don't use for disassembly.  */
   *invalid = 1;
   return -value;
 }