diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c
index 8793b4e322b0..0f9cd703e725 100644
--- a/tools/perf/util/evlist.c
+++ b/tools/perf/util/evlist.c
@@ -21,6 +21,7 @@
 #include "../perf.h"
 #include "asm/bug.h"
 #include "bpf-event.h"
+#include "util/string2.h"
 #include <signal.h>
 #include <unistd.h>
 #include <sched.h>
@@ -959,7 +960,7 @@ int perf_evlist__append_tp_filter(struct evlist *evlist, const char *filter)
 	return err;
 }
 
-static char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
+char *asprintf__tp_filter_pids(size_t npids, pid_t *pids)
 {
 	char *filter;
 	size_t i;
diff --git a/tools/perf/util/string2.h b/tools/perf/util/string2.h
index 708805f5573e..73df616ced43 100644
--- a/tools/perf/util/string2.h
+++ b/tools/perf/util/string2.h
@@ -4,6 +4,7 @@
 
 #include <linux/string.h>
 #include <linux/types.h>
+#include <sys/types.h> // pid_t
 #include <stddef.h>
 #include <string.h>
 
@@ -32,6 +33,8 @@ static inline char *asprintf_expr_not_in_ints(const char *var, size_t nints, int
 	return asprintf_expr_inout_ints(var, false, nints, ints);
 }
 
+char *asprintf__tp_filter_pids(size_t npids, pid_t *pids);
+
 char *strpbrk_esc(char *str, const char *stopset);
 char *strdup_esc(const char *str);