diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 7bb84c4a8f299eff16407c7c1d41c9095cb8f16f..43c05eae176833641ca1972579d4662dd43780ed 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1015,7 +1015,9 @@ static struct syscall_fmt syscall_fmts[] = {
 	.alias = "old_mmap",
 #endif
 	  .arg = { [2] = { .scnprintf = SCA_MMAP_PROT,	/* prot */ },
-		   [3] = { .scnprintf = SCA_MMAP_FLAGS,	/* flags */ },
+		   [3] = { .scnprintf = SCA_MMAP_FLAGS,	/* flags */
+			   .strtoul   = STUL_STRARRAY_FLAGS,
+			   .parm      = &strarray__mmap_flags, },
 		   [5] = { .scnprintf = SCA_HEX,	/* offset */ }, }, },
 	{ .name	    = "mount",
 	  .arg = { [0] = { .scnprintf = SCA_FILENAME, /* dev_name */ },