diff --git a/src/security_headers_middleware_test.cpp b/src/security_headers_middleware_test.cpp
index f5cd3d5..80df725 100644
--- a/src/security_headers_middleware_test.cpp
+++ b/src/security_headers_middleware_test.cpp
@@ -33,7 +33,7 @@
                 c.close();
                 break;
             }
-            catch (std::exception e)
+            catch (const std::exception& e)
             {
                 // do nothing.  We expect this to fail while the server is
                 // starting up