diff --git a/test/source/signal.cpp b/test/source/signal.cpp
index c99aa6b..d3b53a7 100644
--- a/test/source/signal.cpp
+++ b/test/source/signal.cpp
@@ -92,6 +92,10 @@
     EXPECT_EQ(1, completions);
     EXPECT_EQ(expected_si, return_si);
 
+    signal.set_callback(std::bind([]() {}));
+    EXPECT_EQ(0, handler(nullptr, expected_si, &signal));
+    EXPECT_EQ(1, completions);
+
     expect_destruct();
 }