diff --git a/tests/expected/libmount/loop-conflict b/tests/expected/libmount/loop-conflict
index e26f99a4f..1686021f0 100644
--- a/tests/expected/libmount/loop-conflict
+++ b/tests/expected/libmount/loop-conflict
@@ -1,2 +1,2 @@
-: overlapping loop device exists
+mount: <target> overlapping loop device exists for <source>
 Success
diff --git a/tests/expected/libmount/loop-o-loop-val-conflict b/tests/expected/libmount/loop-o-loop-val-conflict
index 043847449..0eb732214 100644
--- a/tests/expected/libmount/loop-o-loop-val-conflict
+++ b/tests/expected/libmount/loop-o-loop-val-conflict
@@ -1,2 +1,2 @@
-: failed to setup loop device: Device or resource busy
+mount: <target> failed to setup loop device for <source>
 Success
diff --git a/tests/expected/libmount/loop-o-loop-val-initialized b/tests/expected/libmount/loop-o-loop-val-initialized
index e26f99a4f..1686021f0 100644
--- a/tests/expected/libmount/loop-o-loop-val-initialized
+++ b/tests/expected/libmount/loop-o-loop-val-initialized
@@ -1,2 +1,2 @@
-: overlapping loop device exists
+mount: <target> overlapping loop device exists for <source>
 Success
diff --git a/tests/expected/libmount/loop-overlay b/tests/expected/libmount/loop-overlay
index ab6c68beb..399024471 100644
--- a/tests/expected/libmount/loop-overlay
+++ b/tests/expected/libmount/loop-overlay
@@ -1,7 +1,7 @@
 second should fail
- overlapping loop device exists
+mount: <target> overlapping loop device exists for <source>
 should succeed
 both should fail
- overlapping loop device exists
- overlapping loop device exists
+mount: <target> overlapping loop device exists for <source>
+mount: <target> overlapping loop device exists for <source>
 Success
diff --git a/tests/ts/libmount/loop b/tests/ts/libmount/loop
index 1589af1ed..ec22c9a2c 100755
--- a/tests/ts/libmount/loop
+++ b/tests/ts/libmount/loop
@@ -104,7 +104,8 @@ ts_finalize_subtest
 ts_init_subtest "conflict"
 [ -d "$TS_MOUNTPOINT" ] || mkdir -p $TS_MOUNTPOINT
 LODEV=$( $TS_CMD_LOSETUP --find --nooverlap --show --offset=1000 "$BACKFILE" 2>> $TS_OUTPUT )
-$TS_CMD_MOUNT "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 | sed 's/^.*\.img//' > $TS_OUTPUT
+$TS_CMD_MOUNT "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 \
+	| sed 's/:.*:/: <target>/; s/for .*/for <source>/' > $TS_OUTPUT
 $TS_CMD_LOSETUP --detach $LODEV >> $TS_OUTPUT 2>&1
 udevadm settle
 ts_log "Success"
@@ -114,7 +115,8 @@ ts_init_subtest "o-loop-val-initialized"
 [ -d "$TS_MOUNTPOINT" ] || mkdir -p $TS_MOUNTPOINT
 LODEV=$( $TS_CMD_LOSETUP --find 2>> $TS_OUTPUT )
 $TS_CMD_LOSETUP $LODEV "$BACKFILE" >> $TS_OUTPUT 2>&1
-$TS_CMD_MOUNT -oloop=$LODEV "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 | sed 's/^.*\.img//' > $TS_OUTPUT
+$TS_CMD_MOUNT -oloop=$LODEV "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 \
+       | sed 's/:.*:/: <target>/; s/for .*/for <source>/' > $TS_OUTPUT
 $TS_CMD_LOSETUP --detach $LODEV >> $TS_OUTPUT 2>&1
 udevadm settle
 ts_log "Success"
@@ -125,7 +127,8 @@ ts_init_subtest "o-loop-val-conflict"
 cp "$BACKFILE" "$BACKFILE"-2
 LODEV=$( $TS_CMD_LOSETUP --find 2>> $TS_OUTPUT )
 $TS_CMD_LOSETUP $LODEV "$BACKFILE"-2 >> $TS_OUTPUT 2>&1
-$TS_CMD_MOUNT -oloop=$LODEV "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 | sed 's/^.*\.img//' > $TS_OUTPUT
+$TS_CMD_MOUNT -oloop=$LODEV "$BACKFILE" "$TS_MOUNTPOINT" 2>&1 \
+	| sed 's/:.*:/: <target>/; s/for .*/for <source>/' > $TS_OUTPUT
 $TS_CMD_LOSETUP --detach $LODEV >> $TS_OUTPUT 2>&1
 rm "$BACKFILE"-2
 udevadm settle
diff --git a/tests/ts/libmount/loop-overlay b/tests/ts/libmount/loop-overlay
index 97eb32118..dc9b73d6b 100755
--- a/tests/ts/libmount/loop-overlay
+++ b/tests/ts/libmount/loop-overlay
@@ -43,8 +43,8 @@ dd if="$IMG" of="$IMG" oflag=append bs=5MiB count=1 conv=notrunc &>/dev/null
 
 echo "second should fail" >>$TS_OUTPUT
 $TS_CMD_MOUNT -oloop "$IMG" "$TS_MOUNTPOINT-1" >> $TS_OUTPUT 2>&1
-$TS_CMD_MOUNT -oloop,offset=$OFFSET "$IMG" "$TS_MOUNTPOINT-2" 2>&1 | sed 's/.*://' >>$TS_OUTPUT
-
+$TS_CMD_MOUNT -oloop,offset=$OFFSET "$IMG" "$TS_MOUNTPOINT-2" 2>&1 \
+       | sed 's/:.*:/: <target>/; s/for .*/for <source>/' >> $TS_OUTPUT
 $TS_CMD_UMOUNT "$TS_MOUNTPOINT-1" >> $TS_OUTPUT 2>&1
 
 echo "should succeed" >>$TS_OUTPUT
@@ -56,8 +56,10 @@ $TS_CMD_UMOUNT "$TS_MOUNTPOINT-2" >> $TS_OUTPUT 2>&1
 echo "both should fail" >>$TS_OUTPUT
 LOOPDEV=$($TS_CMD_LOSETUP --find)
 $TS_CMD_LOSETUP --offset 1 --sizelimit $OFFSET $LOOPDEV "$IMG"
-$TS_CMD_MOUNT -oloop,sizelimit=$OFFSET "$IMG" "$TS_MOUNTPOINT-1" 2>&1 | sed 's/.*://' >>$TS_OUTPUT
-$TS_CMD_MOUNT -oloop,offset=$OFFSET "$IMG" "$TS_MOUNTPOINT-2" 2>&1 | sed 's/.*://' >>$TS_OUTPUT
+$TS_CMD_MOUNT -oloop,sizelimit=$OFFSET "$IMG" "$TS_MOUNTPOINT-1" 2>&1 \
+	| sed 's/:.*:/: <target>/; s/for .*/for <source>/' >> $TS_OUTPUT
+$TS_CMD_MOUNT -oloop,offset=$OFFSET "$IMG" "$TS_MOUNTPOINT-2" 2>&1 \
+	| sed 's/:.*:/: <target>/; s/for .*/for <source>/' >> $TS_OUTPUT
 $TS_CMD_LOSETUP --detach $LOOPDEV
 
 ts_log "Success"