diff --git a/src/Runner.Worker/ActionRunner.cs b/src/Runner.Worker/ActionRunner.cs
index 0c4cc76ce..81ecf1a14 100644
--- a/src/Runner.Worker/ActionRunner.cs
+++ b/src/Runner.Worker/ActionRunner.cs
@@ -187,13 +187,19 @@ namespace GitHub.Runner.Worker
             // Validate inputs only for actions with action.yml
             if (Action.Reference.Type == Pipelines.ActionSourceType.Repository)
             {
+                var unexpectedInputs = new List<string>();
                 foreach (var input in userInputs)
                 {
                     if (!validInputs.Contains(input))
                     {
-                        ExecutionContext.Warning($"Unexpected input '{input}', valid inputs are ['{string.Join("', '", validInputs)}']");
+                        unexpectedInputs.Add(input);
                     }
                 }
+
+                if (unexpectedInputs.Count > 0)
+                {
+                    ExecutionContext.Warning($"Unexpected input(s) '{string.Join("', '", unexpectedInputs)}', valid inputs are ['{string.Join("', '", validInputs)}']");
+                }
             }
 
             // Load the action environment.
diff --git a/src/Test/L0/Worker/ActionRunnerL0.cs b/src/Test/L0/Worker/ActionRunnerL0.cs
index f8185d26d..662ea307d 100644
--- a/src/Test/L0/Worker/ActionRunnerL0.cs
+++ b/src/Test/L0/Worker/ActionRunnerL0.cs
@@ -328,8 +328,7 @@ namespace GitHub.Runner.Common.Tests.Worker
             Assert.Equal("invalid1", finialInputs["invalid1"]);
             Assert.Equal("invalid2", finialInputs["invalid2"]);
 
-            _ec.Verify(x => x.AddIssue(It.Is<Issue>(s => s.Message.Contains("Unexpected input 'invalid1'")), It.IsAny<string>()), Times.Once);
-            _ec.Verify(x => x.AddIssue(It.Is<Issue>(s => s.Message.Contains("Unexpected input 'invalid2'")), It.IsAny<string>()), Times.Once);
+            _ec.Verify(x => x.AddIssue(It.Is<Issue>(s => s.Message.Contains("Unexpected input(s) 'invalid1', 'invalid2'")), It.IsAny<string>()), Times.Once);
         }
 
         private void Setup([CallerMemberName] string name = "")