diff --git a/configure b/configure
index 36184a58ad..742cb7c533 100755
--- a/configure
+++ b/configure
@@ -864,7 +864,8 @@ cat > $TMPC <<EOF
 #include <signal.h> /* pthread_sigmask() */
 int main(void)
 {
-  return pthread_sigmask(0, NULL, NULL);
+  sigset_t sigmask;
+  return pthread_sigmask(0, NULL, &sigmask);
 }
 EOF
 if compile_prog "" "$LIBS" "pthread_sigmask" ; then
diff --git a/helper_thread.c b/helper_thread.c
index 53dea44bab..2a9dabf5f7 100644
--- a/helper_thread.c
+++ b/helper_thread.c
@@ -106,13 +106,14 @@ static int read_from_pipe(int fd, void *buf, size_t len)
 
 static void block_signals(void)
 {
-#ifdef HAVE_PTHREAD_SIGMASK
+#ifdef CONFIG_PTHREAD_SIGMASK
 	sigset_t sigmask;
 
+	int ret;
+
 	ret = pthread_sigmask(SIG_UNBLOCK, NULL, &sigmask);
 	assert(ret == 0);
 	ret = pthread_sigmask(SIG_BLOCK, &sigmask, NULL);
-	assert(ret == 0);
 #endif
 }