diff --git a/packages/webdriverio/src/commands/element/getSize.ts b/packages/webdriverio/src/commands/element/getSize.ts
index d214fec8f44..ae9851681dc 100644
--- a/packages/webdriverio/src/commands/element/getSize.ts
+++ b/packages/webdriverio/src/commands/element/getSize.ts
@@ -47,7 +47,7 @@ async function getSize (
         rect = await this.getElementSize(this.elementId) as RectReturn
     }
 
-    if (prop && rect[prop]) {
+    if (prop && typeof rect[prop] === 'number') {
         return rect[prop] as number
     }
 
diff --git a/packages/webdriverio/tests/commands/element/getSize.test.ts b/packages/webdriverio/tests/commands/element/getSize.test.ts
index 7d043b4df4c..8adcb8c7f07 100644
--- a/packages/webdriverio/tests/commands/element/getSize.test.ts
+++ b/packages/webdriverio/tests/commands/element/getSize.test.ts
@@ -54,6 +54,8 @@ describe('getSize test', () => {
         expect(width).toBe(50)
         const height = await elem.getSize('height')
         expect(height).toBe(30)
+        const invalid = await elem.getSize('foobar')
+        expect(invalid).toEqual({ width: 50, height: 30 })
     })
 
     afterEach(() => {