diff --git a/ChangeLog.md b/ChangeLog.md
index 1001e734..4e587ba9 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -24,6 +24,16 @@ JPEG images.  This was known to cause a buffer overflow when attempting to
 decompress some such images using `tjDecompressToYUV2()` or
 `tjDecompressToYUVPlanes()`.
 
+5. Fixed an issue, detected by ASan, whereby attempting to losslessly transform
+a specially-crafted malformed JPEG image containing an extremely-high-frequency
+coefficient block (junk image data that could never be generated by a
+legitimate JPEG compressor) could cause the Huffman encoder's local buffer to
+be overrun. (Refer to 1.4.0[9] and 1.4beta1[15].)  Given that the buffer
+overrun was fully contained within the stack and did not cause a segfault or
+other user-visible errant behavior, and given that the lossless transformer
+(unlike the decompressor) is not generally exposed to arbitrary data exploits,
+this issue did not likely pose a security risk.
+
 
 2.0.3
 =====
diff --git a/jchuff.c b/jchuff.c
index 206958e2..cb05055d 100644
--- a/jchuff.c
+++ b/jchuff.c
@@ -432,7 +432,7 @@ dump_buffer(working_state *state)
  * scanning order-- 1, 8, 16, etc.), then this will produce an encoded block
  * larger than 200 bytes.
  */
-#define BUFSIZE  (DCTSIZE2 * 4)
+#define BUFSIZE  (DCTSIZE2 * 8)
 
 #define LOAD_BUFFER() { \
   if (state->free_in_buffer < BUFSIZE) { \