diff --git a/log_merge.sh b/log_merge.sh
index 0a3066e..df52cfe 100755
--- a/log_merge.sh
+++ b/log_merge.sh
@@ -18,8 +18,8 @@
 TEST_CASES=`ls -1 $LOG_FILES | awk 'BEGIN { FS = "-" } { print $2 }' | sort | uniq`
 
 for t in $TEST_CASES; do
-	PREFIX="$BASE_NAME.$t"
-	OUTPUT="$PREFIX.merged"
+	PREFIX="$BASE_NAME-$t"
+	OUTPUT="$BASE_NAME.$t.merged"
 	ttcn3_logmerge $PREFIX-*.log > $OUTPUT
 	echo "Generated $OUTPUT"
 done