diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/MessageHandlerFactory.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/MessageHandlerFactory.java
index 62cad85070d..1dd6eadc7fd 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/MessageHandlerFactory.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/MessageHandlerFactory.java
@@ -27,8 +27,8 @@ import javax.websocket.MessageHandler;
 
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 import org.eclipse.jetty.websocket.jsr356.metadata.MessageHandlerMetadata;
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
 
 /**
  * Factory for {@link MessageHandlerMetadata}
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/AnnotatedEndpointScanner.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/AnnotatedEndpointScanner.java
index 50572389be5..70075e47b7b 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/AnnotatedEndpointScanner.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/AnnotatedEndpointScanner.java
@@ -33,7 +33,7 @@ import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
 import org.eclipse.jetty.websocket.common.events.annotated.AbstractMethodAnnotationScanner;
 import org.eclipse.jetty.websocket.common.events.annotated.InvalidSignatureException;
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 
 public class AnnotatedEndpointScanner<T extends Annotation, C extends EndpointConfig> extends AbstractMethodAnnotationScanner<AnnotatedEndpointMetadata<T, C>>
 {
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/OnMessageCallable.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/OnMessageCallable.java
index d2998bcc7d2..3b2d6fd1cb5 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/OnMessageCallable.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/OnMessageCallable.java
@@ -24,10 +24,10 @@ import javax.websocket.Decoder;
 import javax.websocket.Encoder;
 
 import org.eclipse.jetty.websocket.common.events.annotated.InvalidSignatureException;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 import org.eclipse.jetty.websocket.jsr356.EncoderFactory;
 import org.eclipse.jetty.websocket.jsr356.InitException;
 import org.eclipse.jetty.websocket.jsr356.JsrSession;
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
 
 public class OnMessageCallable extends JsrCallable
 {
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/Param.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/Param.java
index 2744e2654a9..fd916d8a4c4 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/Param.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/annotations/Param.java
@@ -18,7 +18,7 @@
 
 package org.eclipse.jetty.websocket.jsr356.annotations;
 
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 
 public class Param
 {
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/DecoderMetadataSet.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/DecoderMetadataSet.java
index 2397b16927a..0307b3caf86 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/DecoderMetadataSet.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/DecoderMetadataSet.java
@@ -25,8 +25,8 @@ import javax.websocket.Decoder;
 
 import org.eclipse.jetty.websocket.api.InvalidWebSocketException;
 import org.eclipse.jetty.websocket.common.events.annotated.InvalidSignatureException;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 import org.eclipse.jetty.websocket.jsr356.MessageType;
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
 
 public class DecoderMetadataSet extends CoderMetadataSet<Decoder, DecoderMetadata>
 {
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/EncoderMetadataSet.java b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/EncoderMetadataSet.java
index a95adcac8c5..5f1b279e0b8 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/EncoderMetadataSet.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/metadata/EncoderMetadataSet.java
@@ -25,8 +25,8 @@ import javax.websocket.Encoder;
 
 import org.eclipse.jetty.websocket.api.InvalidWebSocketException;
 import org.eclipse.jetty.websocket.common.events.annotated.InvalidSignatureException;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 import org.eclipse.jetty.websocket.jsr356.MessageType;
-import org.eclipse.jetty.websocket.jsr356.utils.ReflectUtils;
 
 public class EncoderMetadataSet extends CoderMetadataSet<Encoder, EncoderMetadata>
 {
diff --git a/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtilsTest.java b/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtilsTest.java
index 222476e2127..f8e040bbee3 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtilsTest.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtilsTest.java
@@ -20,6 +20,7 @@ package org.eclipse.jetty.websocket.jsr356.utils;
 
 import static org.hamcrest.Matchers.*;
 
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 import org.junit.Assert;
 import org.junit.Test;
 
diff --git a/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/TypeTree.java b/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/TypeTree.java
index a00216a7a48..648ebd41d09 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/TypeTree.java
+++ b/jetty-websocket/javax-websocket-client-impl/src/test/java/org/eclipse/jetty/websocket/jsr356/utils/TypeTree.java
@@ -24,6 +24,8 @@ import java.lang.reflect.Type;
 import java.lang.reflect.TypeVariable;
 import java.lang.reflect.WildcardType;
 
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
+
 public class TypeTree
 {
     public static void dumpTree(String indent, Type type)
diff --git a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/events/annotated/CallableMethod.java b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/events/annotated/CallableMethod.java
index 503f909bc52..1b404511467 100644
--- a/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/events/annotated/CallableMethod.java
+++ b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/events/annotated/CallableMethod.java
@@ -25,6 +25,7 @@ import java.util.Objects;
 import org.eclipse.jetty.util.log.Log;
 import org.eclipse.jetty.util.log.Logger;
 import org.eclipse.jetty.websocket.api.WebSocketException;
+import org.eclipse.jetty.websocket.common.util.ReflectUtils;
 
 /**
  * A Callable Method
@@ -71,8 +72,31 @@ public class CallableMethod
         }
         catch (IllegalAccessException | IllegalArgumentException | InvocationTargetException e)
         {
-            String err = String.format("Cannot call method %s on %s with args: %s",method,pojo,args);
-            throw new WebSocketException(err,e);
+            StringBuilder err = new StringBuilder();
+            err.append("Cannot call method ");
+            err.append(ReflectUtils.toString(pojo,method));
+            err.append(" with args: [");
+
+            boolean delim = false;
+            for (Object arg : args)
+            {
+                if (delim)
+                {
+                    err.append(", ");
+                }
+                if (arg == null)
+                {
+                    err.append("<null>");
+                }
+                else
+                {
+                    err.append(arg.getClass().getName());
+                }
+                delim = true;
+            }
+            err.append("]");
+
+            throw new WebSocketException(err.toString(),e);
         }
     }
 
diff --git a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtils.java b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/util/ReflectUtils.java
similarity index 99%
rename from jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtils.java
rename to jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/util/ReflectUtils.java
index 3b14860f400..eb6e3c52b52 100644
--- a/jetty-websocket/javax-websocket-client-impl/src/main/java/org/eclipse/jetty/websocket/jsr356/utils/ReflectUtils.java
+++ b/jetty-websocket/websocket-common/src/main/java/org/eclipse/jetty/websocket/common/util/ReflectUtils.java
@@ -16,7 +16,7 @@
 //  ========================================================================
 //
 
-package org.eclipse.jetty.websocket.jsr356.utils;
+package org.eclipse.jetty.websocket.common.util;
 
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Method;
@@ -344,8 +344,7 @@ public class ReflectUtils
     public static String toString(Class<?> pojo, Method method)
     {
         StringBuilder str = new StringBuilder();
-        str.append(pojo.getName());
-        str.append("  ");
+
         // method modifiers
         int mod = method.getModifiers() & Modifier.methodModifiers();
         if (mod != 0)
@@ -357,6 +356,10 @@ public class ReflectUtils
         Type retType = method.getGenericReturnType();
         appendTypeName(str,retType,false).append(' ');
 
+        // class name
+        str.append(pojo.getName());
+        str.append("#");
+
         // method name
         str.append(method.getName());