diff --git a/ChangeLog.txt b/ChangeLog.txt
index 468f09039..1bdc1b0f4 100644
--- a/ChangeLog.txt
+++ b/ChangeLog.txt
@@ -15,6 +15,11 @@ SIMD code with NASM 0.98.
 [4] Fixed a Huffman encoder bug that prevented I/O suspension from working
 properly.
 
+[5] Fixed a bug whereby attempting to encode a progressive JPEG with arithmetic
+entropy coding (by passing arguments of -progressive -arithmetic to cjpeg or
+jpegtran, for instance) would result in an error, "Requested feature was
+omitted at compile time".
+
 
 1.2.1
 =====
diff --git a/jcmaster.c b/jcmaster.c
index bee0cafc8..accfc7017 100644
--- a/jcmaster.c
+++ b/jcmaster.c
@@ -602,7 +602,7 @@ jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)
     cinfo->num_scans = 1;
   }
 
-  if (cinfo->progressive_mode)	/*  TEMPORARY HACK ??? */
+  if (cinfo->progressive_mode && !cinfo->arith_code)	/*  TEMPORARY HACK ??? */
     cinfo->optimize_coding = TRUE; /* assume default tables no good for progressive mode */
 
   /* Initialize my private state */