diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index a36e98c7a1c5..c42bc608954e 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -1033,7 +1033,7 @@ static const struct syscall_fmt syscall_fmts[] = {
 #if defined(__s390x__)
 	.alias = "old_mmap",
 #endif
-	  .arg = { [2] = { .scnprintf = SCA_MMAP_PROT,	/* prot */ },
+	  .arg = { [2] = { .scnprintf = SCA_MMAP_PROT, .show_zero = true, /* prot */ },
 		   [3] = { .scnprintf = SCA_MMAP_FLAGS,	/* flags */
 			   .strtoul   = STUL_STRARRAY_FLAGS,
 			   .parm      = &strarray__mmap_flags, },
@@ -1050,7 +1050,7 @@ static const struct syscall_fmt syscall_fmts[] = {
 		   [4] = { .scnprintf = SCA_MOVE_MOUNT_FLAGS, /* flags */ }, }, },
 	{ .name	    = "mprotect",
 	  .arg = { [0] = { .scnprintf = SCA_HEX,	/* start */ },
-		   [2] = { .scnprintf = SCA_MMAP_PROT,	/* prot */ }, }, },
+		   [2] = { .scnprintf = SCA_MMAP_PROT, .show_zero = true, /* prot */ }, }, },
 	{ .name	    = "mq_unlink",
 	  .arg = { [0] = { .scnprintf = SCA_FILENAME, /* u_name */ }, }, },
 	{ .name	    = "mremap",	    .hexret = true,
@@ -1084,7 +1084,7 @@ static const struct syscall_fmt syscall_fmts[] = {
 	  .arg = { [0] = { .scnprintf = SCA_INT,	/* key */ }, }, },
 	{ .name	    = "pkey_mprotect",
 	  .arg = { [0] = { .scnprintf = SCA_HEX,	/* start */ },
-		   [2] = { .scnprintf = SCA_MMAP_PROT,	/* prot */ },
+		   [2] = { .scnprintf = SCA_MMAP_PROT, .show_zero = true, /* prot */ },
 		   [3] = { .scnprintf = SCA_INT,	/* pkey */ }, }, },
 	{ .name	    = "poll", .timeout = true, },
 	{ .name	    = "ppoll", .timeout = true, },