diff --git a/ChangeLog.md b/ChangeLog.md
index 2c438ad..89a6c68 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -100,6 +100,10 @@
 12. The ARM 64-bit (ARMv8) NEON SIMD extensions can now be built using MinGW
 toolchains targetting ARM64 (AArch64) Windows binaries.
 
+4. Fixed unexpected visual artifacts that occurred when using
+`jpeg_crop_scanline()` and interblock smoothing while decompressing only the
+DC scan of a progressive JPEG image.
+
 
 2.0.5
 =====
@@ -512,9 +516,9 @@
 `jpeg_consume_input()` would return `JPEG_SUSPENDED` rather than
 `JPEG_REACHED_EOI`.
 
-9. `jpeg_crop_scanlines()` now works correctly when decompressing grayscale
-JPEG images that were compressed with a sampling factor other than 1 (for
-instance, with `cjpeg -grayscale -sample 2x2`).
+9. `jpeg_crop_scanline()` now works correctly when decompressing grayscale JPEG
+images that were compressed with a sampling factor other than 1 (for instance,
+with `cjpeg -grayscale -sample 2x2`).
 
 
 1.5.2
@@ -538,7 +542,7 @@
 5. Fixed build and runtime errors on Windows that occurred when building
 libjpeg-turbo with libjpeg v7 API/ABI emulation and the in-memory
 source/destination managers.  Due to an oversight, the `jpeg_skip_scanlines()`
-and `jpeg_crop_scanlines()` functions were not being included in jpeg7.dll when
+and `jpeg_crop_scanline()` functions were not being included in jpeg7.dll when
 libjpeg-turbo was built with `-DWITH_JPEG7=1` and `-DWITH_MEMSRCDST=1`.
 
 6. Fixed "Bogus virtual array access" error that occurred when using the
diff --git a/jdcoefct.c b/jdcoefct.c
index 9343abe..ea2febd 100644
--- a/jdcoefct.c
+++ b/jdcoefct.c
@@ -6,7 +6,7 @@
  * libjpeg-turbo Modifications:
  * Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
  * Copyright (C) 2010, 2015-2016, 2019, D. R. Commander.
- * Copyright (C) 2015, Google, Inc.
+ * Copyright (C) 2015, 2020, Google, Inc.
  * For conditions of distribution and use, see the accompanying README.ijg
  * file.
  *
@@ -512,11 +512,13 @@
       if (first_row && block_row == 0)
         prev_block_row = buffer_ptr;
       else
-        prev_block_row = buffer[block_row - 1];
+        prev_block_row = buffer[block_row - 1] +
+                         cinfo->master->first_MCU_col[ci];
       if (last_row && block_row == block_rows - 1)
         next_block_row = buffer_ptr;
       else
-        next_block_row = buffer[block_row + 1];
+        next_block_row = buffer[block_row + 1] +
+                         cinfo->master->first_MCU_col[ci];
       /* We fetch the surrounding DC values using a sliding-register approach.
        * Initialize all nine here so as to do the right thing on narrow pics.
        */