diff --git a/__tests__/buildx/buildx.test.ts b/__tests__/buildx/buildx.test.ts
index b5c53f6..503667a 100644
--- a/__tests__/buildx/buildx.test.ts
+++ b/__tests__/buildx/buildx.test.ts
@@ -157,7 +157,7 @@ describe('printVersion', () => {
 describe('version', () => {
   it('valid', async () => {
     const buildx = new Buildx();
-    expect(semver.valid(await buildx.version)).not.toBeUndefined();
+    expect(semver.valid(await buildx.version())).not.toBeUndefined();
   });
 });
 
diff --git a/__tests__/docker.test.ts b/__tests__/docker.test.ts
index c8a7415..416f1a4 100644
--- a/__tests__/docker.test.ts
+++ b/__tests__/docker.test.ts
@@ -52,7 +52,7 @@ describe('isAvailable', () => {
     const execSpy = jest.spyOn(Exec, 'getExecOutput');
     await Docker.isAvailable();
     // eslint-disable-next-line jest/no-standalone-expect
-    expect(execSpy).toHaveBeenCalledWith(`docker`, undefined, {
+    expect(execSpy).toHaveBeenCalledWith(`docker`, [], {
       silent: true,
       ignoreReturnCode: true
     });
diff --git a/src/buildkit/buildkit.ts b/src/buildkit/buildkit.ts
index 30bd8b8..9abbe78 100644
--- a/src/buildkit/buildkit.ts
+++ b/src/buildkit/buildkit.ts
@@ -80,17 +80,17 @@ export class BuildKit {
       builderInfo = await new Builder({buildx: this.buildx}).inspect(builderName);
     }
     for (const node of builderInfo.nodes) {
-      core.debug(`BuildKit.versionSatisfies ${node}: ${range}`);
       let bkversion = node.buildkitVersion;
+      core.debug(`BuildKit.versionSatisfies ${bkversion}: ${range}`);
       if (!bkversion) {
         try {
           bkversion = await this.getVersionWithinImage(node.name || '');
         } catch (e) {
-          core.debug(`BuildKit.versionSatisfies ${node}: can't get version`);
+          core.debug(`BuildKit.versionSatisfies ${node.name}: can't get version`);
           return false;
         }
       }
-      core.debug(`BuildKit.versionSatisfies ${node}: version ${bkversion}`);
+      core.debug(`BuildKit.versionSatisfies ${node.name}: version ${bkversion}`);
       // BuildKit version reported by moby is in the format of `v0.11.0-moby`
       if (builderInfo.driver == 'docker' && !bkversion.endsWith('-moby')) {
         return false;
diff --git a/src/buildx/buildx.ts b/src/buildx/buildx.ts
index fbf3d64..c59b89e 100644
--- a/src/buildx/buildx.ts
+++ b/src/buildx/buildx.ts
@@ -30,7 +30,8 @@ export interface BuildxOpts {
 }
 
 export class Buildx {
-  private _version: string | undefined;
+  private _version: string;
+  private _versionOnce: boolean;
   private readonly _standalone: boolean | undefined;
 
   public readonly inputs: Inputs;
@@ -39,6 +40,8 @@ export class Buildx {
 
   constructor(opts?: BuildxOpts) {
     this._standalone = opts?.standalone;
+    this._version = '';
+    this._versionOnce = false;
     this.inputs = new Inputs();
   }
 
@@ -94,22 +97,22 @@ export class Buildx {
     });
   }
 
-  get version() {
-    return (async () => {
-      if (!this._version) {
-        const cmd = await this.getCommand(['version']);
-        this._version = await Exec.getExecOutput(cmd.command, cmd.args, {
-          ignoreReturnCode: true,
-          silent: true
-        }).then(res => {
-          if (res.stderr.length > 0 && res.exitCode != 0) {
-            throw new Error(res.stderr.trim());
-          }
-          return Buildx.parseVersion(res.stdout.trim());
-        });
-      }
+  public async version(): Promise<string> {
+    if (this._versionOnce) {
       return this._version;
-    })();
+    }
+    this._versionOnce = true;
+    const cmd = await this.getCommand(['version']);
+    this._version = await Exec.getExecOutput(cmd.command, cmd.args, {
+      ignoreReturnCode: true,
+      silent: true
+    }).then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+      return Buildx.parseVersion(res.stdout.trim());
+    });
+    return this._version;
   }
 
   public async printVersion() {
@@ -128,7 +131,7 @@ export class Buildx {
   }
 
   public async versionSatisfies(range: string, version?: string): Promise<boolean> {
-    const ver = version ?? (await this.version);
+    const ver = version ?? (await this.version());
     if (!ver) {
       core.debug(`Buildx.versionSatisfies false: undefined version`);
       return false;
diff --git a/src/docker.ts b/src/docker.ts
index e959ac9..3760735 100644
--- a/src/docker.ts
+++ b/src/docker.ts
@@ -25,7 +25,7 @@ export class Docker {
   }
 
   public static async isAvailable(): Promise<boolean> {
-    const ok: boolean = await Exec.getExecOutput('docker', undefined, {
+    const ok: boolean = await Exec.getExecOutput('docker', [], {
       ignoreReturnCode: true,
       silent: true
     })