diff --git a/tests/blocksig.c b/tests/blocksig.c
new file mode 100644
index 000000000..13b55e7fc
--- /dev/null
+++ b/tests/blocksig.c
@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <signal.h>
+#include <unistd.h>
+
+int main(int argc, char **argv)
+{
+	sigset_t new_sig, old_sig;
+
+	sigfillset(&new_sig);
+	sigprocmask(SIG_SETMASK, &new_sig, &old_sig);
+	printf("old_sig: %16Lx\n", *(unsigned long long*)&old_sig);
+	printf("new_sig: %16Lx\n", *(unsigned long long*)&new_sig);
+	
+	argc--; argv++;
+	return argc ? execvp(*argv, argv) : 0;
+}