diff --git a/packages/react-reconciler/src/ReactFiberClassComponent.js b/packages/react-reconciler/src/ReactFiberClassComponent.js
index f802c261ba418..6bf04da4b41b6 100644
--- a/packages/react-reconciler/src/ReactFiberClassComponent.js
+++ b/packages/react-reconciler/src/ReactFiberClassComponent.js
@@ -1274,7 +1274,7 @@ export function resolveClassComponentProps(
     // We may have already copied the props object above to remove ref. If so,
     // we can modify that. Otherwise, copy the props object with Object.assign.
     if (newProps === baseProps) {
-      newProps = assign({}, newProps, baseProps);
+      newProps = assign({}, newProps);
     }
     // Taken from old JSX runtime, where this used to live.
     for (const propName in defaultProps) {