diff --git a/src/kvm_websocket_test.cpp b/src/kvm_websocket_test.cpp
index 4016329..c01b7e5 100644
--- a/src/kvm_websocket_test.cpp
+++ b/src/kvm_websocket_test.cpp
@@ -40,7 +40,7 @@
                 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
@@ -111,4 +111,4 @@
     EXPECT_EQ(open_string, "RFB 003.008");
 
     app.stop();
-}
\ No newline at end of file
+}
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
diff --git a/src/token_authorization_middleware_test.cpp b/src/token_authorization_middleware_test.cpp
index fcb5b65..a93f8c8 100644
--- a/src/token_authorization_middleware_test.cpp
+++ b/src/token_authorization_middleware_test.cpp
@@ -89,7 +89,7 @@
             c.connect(asio::ip::tcp::endpoint(
                 asio::ip::address::from_string("127.0.0.1"), 45451));
         }
-        catch (std::exception e)
+        catch (const std::exception& e)
         {
             // do nothing
         }
@@ -123,7 +123,7 @@
             c.connect(asio::ip::tcp::endpoint(
                 asio::ip::address::from_string("127.0.0.1"), 45451));
         }
-        catch (std::exception e)
+        catch (const std::exception& e)
         {
             // do nothing
         }
@@ -169,7 +169,7 @@
                 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
@@ -259,7 +259,7 @@
                 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