diff --git a/CHANGELOG.md b/CHANGELOG.md
index b2d244bc..01cdd0be 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # MobX-React Changelog
 
+### 6.2.4
+
+-  Fix error thrown in the already defined observer class component warning message when attempting to get the components display name.  [#887](https://github.com/mobxjs/mobx-react/issues/887)
+
 ### 6.2.3
 
 -   Log warning if class component is already an observer to prevent memory leaks.  [#839](https://github.com/mobxjs/mobx-react/issues/839)
diff --git a/src/observerClass.ts b/src/observerClass.ts
index 85762688..29f12696 100644
--- a/src/observerClass.ts
+++ b/src/observerClass.ts
@@ -23,7 +23,7 @@ export function makeClassComponentObserver(
     const target = componentClass.prototype
 
     if (componentClass[mobxObserverProperty]) {
-        const displayName = getDisplayName(this)
+        const displayName = getDisplayName(target)
         console.warn(
             `The provided component class (${displayName}) 
                 has already been declared as an observer component.`