diff --git a/bin/disk-image-create b/bin/disk-image-create
index db76ce38..4a86860b 100755
--- a/bin/disk-image-create
+++ b/bin/disk-image-create
@@ -241,9 +241,6 @@ if [ -n "$DIB_IMAGE_SIZE" ]; then
   du_size=$(echo "$DIB_IMAGE_SIZE" | awk '{printf("%d\n",$1 * 1024 *1024)}')
 else
   # in kb*0.60 - underreport to get a slightly bigger device
-  # Rounding down size so that is is a multiple of 64, works around a bug in
-  # qemu-img that may occur when compressing raw images that aren't a multiple
-  # of 64k. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1180021
   du_size=$(sudo du --block-size=600 -x -s ${TMP_BUILD_DIR}/built |\
             awk ' { print $1 }')
 fi
@@ -252,11 +249,18 @@ if [ "$FS_TYPE" = "ext4" ] ; then
   # We set journal size to 64M so our journal is large enough when we
   # perform an FS resize.
   MKFS_OPTS="-i 4096 -J size=64 $MKFS_OPTS"
-  du_size=$(( $du_size + 65536 ))
+  # Grow the image size to account for the journal, only if the user
+  # has not asked for a specific size.
+  if [ -z "$DIB_IMAGE_SIZE" ]; then
+    du_size=$(( $du_size + 65536 ))
+  fi
 fi
 
-_NEEDED_SIZE=$(echo "$du_size" | awk ' { print $1 + 64 - ( $1 % 64) } ')
-truncate -s${_NEEDED_SIZE}K $TMP_IMAGE_PATH
+# Rounding down size so that is is a multiple of 64, works around a bug in
+# qemu-img that may occur when compressing raw images that aren't a multiple
+# of 64k. https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1180021
+du_size=$(echo "$du_size" | awk ' { if ($1 % 64 != 0) print $1 + 64 - ( $1 % 64); else print $1; } ')
+truncate -s${du_size}K $TMP_IMAGE_PATH
 
 if [ -n "$MAX_ONLINE_RESIZE" ]; then
     MKFS_OPTS="-E resize=$MAX_ONLINE_RESIZE $MKFS_OPTS"