diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index c1fce7f33c..5345dfb2bf 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,7 @@
+2019-12-11  Alan Modra  <amodra@gmail.com>
+
+	* ns32k-dis.c (sign_extend): Correct last patch.
+
 2019-12-11  Alan Modra  <amodra@gmail.com>
 
 	* vax-dis.c (NEXTLONG): Avoid signed overflow.
diff --git a/opcodes/ns32k-dis.c b/opcodes/ns32k-dis.c
index 5e6f0964b7..e43fff712a 100644
--- a/opcodes/ns32k-dis.c
+++ b/opcodes/ns32k-dis.c
@@ -327,8 +327,8 @@ bit_copy (bfd_byte *buffer, int offset, int count, char *to)
 static int
 sign_extend (unsigned int value, unsigned int bits)
 {
-  unsigned int sign = 1u << bits;
-  return ((value & (sign - 1)) ^ sign) - sign;
+  unsigned int sign = 1u << (bits - 1);
+  return ((value & (sign + sign - 1)) ^ sign) - sign;
 }
 
 static void