diff --git a/src/runtime/cgo/gcc_sigaction.c b/src/runtime/cgo/gcc_sigaction.c
index 566097fa6d7..72fb08d720e 100644
--- a/src/runtime/cgo/gcc_sigaction.c
+++ b/src/runtime/cgo/gcc_sigaction.c
@@ -10,6 +10,8 @@
 #include <string.h>
 #include <signal.h>
 
+#include "libcgo.h"
+
 // go_sigaction_t is a C version of the sigactiont struct from
 // defs_linux_amd64.go.  This definition — and its conversion to and from struct
 // sigaction — are specific to linux/amd64.
@@ -33,6 +35,8 @@ x_cgo_sigaction(intptr_t signum, const go_sigaction_t *goact, go_sigaction_t *ol
 	struct sigaction oldact;
 	int i;
 
+	_cgo_tsan_acquire();
+
 	memset(&act, 0, sizeof act);
 	memset(&oldact, 0, sizeof oldact);
 
@@ -53,7 +57,8 @@ x_cgo_sigaction(intptr_t signum, const go_sigaction_t *goact, go_sigaction_t *ol
 
 	ret = sigaction(signum, goact ? &act : NULL, oldgoact ? &oldact : NULL);
 	if (ret == -1) {
-		/* This is what the Go code expects on failure. */
+		// runtime.rt_sigaction expects _cgo_sigaction to return errno on error.
+		_cgo_tsan_release();
 		return errno;
 	}
 
@@ -72,5 +77,6 @@ x_cgo_sigaction(intptr_t signum, const go_sigaction_t *goact, go_sigaction_t *ol
 		oldgoact->flags = oldact.sa_flags;
 	}
 
+	_cgo_tsan_release();
 	return ret;
 }