diff --git a/tools/perf/perf.h b/tools/perf/perf.h
index 08b0b5e..914c895 100644
--- a/tools/perf/perf.h
+++ b/tools/perf/perf.h
@@ -183,4 +183,6 @@
 extern bool perf_host, perf_guest;
 extern const char perf_version_string[];
 
+void pthread__unblock_sigwinch(void);
+
 #endif