diff --git a/src/protocol/http/src/main/java/org/apache/jmeter/protocol/http/sampler/HTTPHC4Impl.java b/src/protocol/http/src/main/java/org/apache/jmeter/protocol/http/sampler/HTTPHC4Impl.java
index 4824ed6a70..fab565a59b 100644
--- a/src/protocol/http/src/main/java/org/apache/jmeter/protocol/http/sampler/HTTPHC4Impl.java
+++ b/src/protocol/http/src/main/java/org/apache/jmeter/protocol/http/sampler/HTTPHC4Impl.java
@@ -255,19 +255,32 @@ public class HTTPHC4Impl extends HTTPHCAbstractImpl {
                     if (!authScope.getRealm().equals(auth.getRealm())) {
                         continue;
                     }
-                    try {
-                        URL authUrl = new URL(auth.getURL());
-                        if (authUrl.getHost().equals(authScope.getHost()) && getPort(authUrl) == authScope.getPort()) {
-                            return auth;
-                        }
-                    } catch (MalformedURLException e) {
-                        log.debug("Invalid URL {} in authManager", auth.getURL());
+                    if (matchesOnUrl(authScope, auth)) {
+                        return auth;
                     }
                 }
             }
             return null;
         }
 
+        private boolean matchesOnUrl(AuthScope authScope, Authorization auth) {
+            String authUrlString = auth.getURL().toLowerCase();
+            try {
+                URL authUrl = new URL(authUrlString);
+                if (authUrl.getHost().equals(authScope.getHost()) && getPort(authUrl) == authScope.getPort()) {
+                    return true;
+                }
+            } catch (MalformedURLException e) {
+                for (String prefix: Arrays.asList("http://", "https://")) {
+                    if ((prefix + authScope.getHost() + ":" + authScope.getPort()).startsWith(authUrlString)) {
+                        return true;
+                    }
+                }
+                log.debug("Invalid URL {} in authManager", authUrlString);
+            }
+            return false;
+        }
+
         private int getPort(URL url) {
             if (url.getPort() == -1) {
                 return url.getProtocol().equals("https") ? 443 : 80;