diff --git a/lib/entry-points.js b/lib/entry-points.js
index ad7ac988a..1a75678e9 100644
--- a/lib/entry-points.js
+++ b/lib/entry-points.js
@@ -170435,12 +170435,24 @@ function fixCodeQualityCategory(logger2, category, env = getEnv()) {
 
 // src/logging.ts
 var core4 = __toESM(require_core());
+var joinMessageStrings = (message) => {
+  if (Array.isArray(message)) {
+    return message.join(" ");
+  } else {
+    return message;
+  }
+};
+var autoJoinMessageStrings = (fn) => {
+  return (message) => {
+    return fn(joinMessageStrings(message));
+  };
+};
 function getActionsLogger() {
   return {
-    debug: core4.debug,
-    info: core4.info,
-    warning: core4.warning,
-    error: core4.error,
+    debug: autoJoinMessageStrings(core4.debug),
+    info: autoJoinMessageStrings(core4.info),
+    warning: autoJoinMessageStrings(core4.warning),
+    error: autoJoinMessageStrings(core4.error),
     isDebug: core4.isDebug,
     startGroup: core4.startGroup,
     endGroup: core4.endGroup
diff --git a/src/logging.test.ts b/src/logging.test.ts
new file mode 100644
index 000000000..33f6f8c16
--- /dev/null
+++ b/src/logging.test.ts
@@ -0,0 +1,17 @@
+import test from "ava";
+
+import { joinMessageStrings } from "./logging";
+import { setupTests } from "./testing-utils";
+
+setupTests(test);
+
+test("joinMessageStrings", async (t) => {
+  // For strings and errors, it is the identity function.
+  t.deepEqual(joinMessageStrings("Hello"), "Hello");
+
+  const error = new Error("Some error");
+  t.deepEqual(joinMessageStrings(error), error);
+
+  // For arrays of strings, we get a join-ed string.
+  t.deepEqual(joinMessageStrings(["foo", "bar"]), "foo bar");
+});
diff --git a/src/logging.ts b/src/logging.ts
index 2c34cb54d..177aca6c7 100644
--- a/src/logging.ts
+++ b/src/logging.ts
@@ -1,10 +1,16 @@
 import * as core from "@actions/core";
 
+/** Types that all of our logging functions accept. */
+export type Loggable = string | string[];
+
+/** Some logging functions also accept errors directly. */
+export type LoggableError = Loggable | Error;
+
 export interface Logger {
-  debug: (message: string) => void;
-  info: (message: string) => void;
-  warning: (message: string | Error) => void;
-  error: (message: string | Error) => void;
+  debug: (message: Loggable) => void;
+  info: (message: Loggable) => void;
+  warning: (message: LoggableError) => void;
+  error: (message: LoggableError) => void;
 
   isDebug: () => boolean;
 
@@ -12,12 +18,33 @@ export interface Logger {
   endGroup: () => void;
 }
 
+/** If `message` is an array of strings, the array is `join`-ed into one string separated by spaces. */
+export const joinMessageStrings = <T>(
+  message: string[] | string | T,
+): string | T => {
+  if (Array.isArray(message)) {
+    return message.join(" ");
+  } else {
+    return message;
+  }
+};
+
+/**
+ * Wraps a logging function so that `joinMessageStrings` is applied to the input before
+ * calling the wrapped logging function.
+ */
+const autoJoinMessageStrings = <T>(fn: (msg: string | T) => void) => {
+  return (message: string[] | string | T) => {
+    return fn(joinMessageStrings(message));
+  };
+};
+
 export function getActionsLogger(): Logger {
   return {
-    debug: core.debug,
-    info: core.info,
-    warning: core.warning,
-    error: core.error,
+    debug: autoJoinMessageStrings(core.debug),
+    info: autoJoinMessageStrings(core.info),
+    warning: autoJoinMessageStrings(core.warning),
+    error: autoJoinMessageStrings(core.error),
     isDebug: core.isDebug,
     startGroup: core.startGroup,
     endGroup: core.endGroup,
diff --git a/src/testing-utils.ts b/src/testing-utils.ts
index a5ba50554..df81f51bb 100644
--- a/src/testing-utils.ts
+++ b/src/testing-utils.ts
@@ -30,7 +30,7 @@ import {
   featureConfig,
   FeatureEnablement,
 } from "./feature-flags";
-import { Logger } from "./logging";
+import { joinMessageStrings, Loggable, LoggableError, Logger } from "./logging";
 import { OverlayDatabaseMode } from "./overlay/overlay-database-mode";
 import { getBundlePlatform } from "./platform";
 import { ActionName } from "./status-report";
@@ -622,8 +622,8 @@ export class RecordingLogger implements Logger {
 
   constructor(private readonly logToConsole: boolean = true) {}
 
-  private addMessage(level: LogLevel, message: string | Error): void {
-    this.messages.push({ type: level, message });
+  private addMessage(level: LogLevel, message: LoggableError): void {
+    this.messages.push({ type: level, message: joinMessageStrings(message) });
 
     if (this.logToConsole) {
       // eslint-disable-next-line no-console
@@ -648,19 +648,19 @@ export class RecordingLogger implements Logger {
     return true;
   }
 
-  debug(message: string) {
+  debug(message: Loggable) {
     this.addMessage("debug", message);
   }
 
-  info(message: string) {
+  info(message: Loggable) {
     this.addMessage("info", message);
   }
 
-  warning(message: string | Error) {
+  warning(message: LoggableError) {
     this.addMessage("warning", message);
   }
 
-  error(message: string | Error) {
+  error(message: LoggableError) {
     this.addMessage("error", message);
   }