diff --git a/perf.py b/perf.py
index 1b9de452..2d83475f 100755
--- a/perf.py
+++ b/perf.py
@@ -336,7 +336,7 @@ def perf(options1, args):
         test_only_r = " sse2-i32x4 sse2-i32x8 sse4-i32x4 sse4-i32x8 sse4-i16x8 \
                         sse4-i8x16 avx1-i32x8 avx1-i32x16 avx1-i64x4 avx1.1-i32x8 \
                         avx1.1-i32x16 avx1.1-i64x4 avx2-i32x8 avx2-i32x16 avx2-i64x4 "
-        test_only = options.perf_target.split(" ")
+        test_only = options.perf_target.split(",")
         for iterator in test_only:
             if not (" " + iterator + " " in test_only_r):
                 error("unknow option for target: " + iterator, 1)