diff --git a/ChangeLog b/ChangeLog
index b3642dbb..cd185d0b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,10 @@
+2013-11-21  Jay Berkenbilt  <ejb@ql.org>
+
+	* Change image comparison tests, which are disabled by default, to
+	use tiff files with 8 bits per sample rather than 4.  This works
+	around a bug in tiffcmp but also increases time and disk space for
+	image comparison tests.
+
 2013-10-28  Jay Berkenbilt  <ejb@ql.org>
 
 	* Fix MacOS compilation errors by adding a missing #include in a
diff --git a/qpdf/qtest/qpdf.test b/qpdf/qtest/qpdf.test
index 1aff3d21..b0390cc1 100644
--- a/qpdf/qtest/qpdf.test
+++ b/qpdf/qtest/qpdf.test
@@ -2176,7 +2176,7 @@ sub compare_pdfs
 	$td->runtest("convert original file to image",
 		     {$td->COMMAND =>
 			  "(cd tif1;" .
-			  " gs 2>/dev/null -q -dNOPAUSE -sDEVICE=tiff12nc" .
+			  " gs 2>/dev/null -q -dNOPAUSE -sDEVICE=tiff24nc" .
 			  " -sOutputFile=a.tif - < ../$f1)"},
 		     {$td->STRING => "",
 		      $td->EXIT_STATUS => 0});
@@ -2195,7 +2195,7 @@ sub compare_pdfs
 	$td->runtest("convert new file to image",
 		     {$td->COMMAND =>
 			  "(cd tif2;" .
-			  " gs 2>/dev/null -q -dNOPAUSE -sDEVICE=tiff12nc" .
+			  " gs 2>/dev/null -q -dNOPAUSE -sDEVICE=tiff24nc" .
 			  " -sOutputFile=a.tif - < ../$f2)"},
 		     {$td->STRING => "",
 		      $td->EXIT_STATUS => 0});