diff --git a/.changeset/selfish-lies-cheer.md b/.changeset/selfish-lies-cheer.md
new file mode 100644
index 00000000000..47a530b8f33
--- /dev/null
+++ b/.changeset/selfish-lies-cheer.md
@@ -0,0 +1,5 @@
+---
+'graphiql': patch
+---
+
+Fixed problem where 'global' variable is referenced when it might not be present (#2155)
diff --git a/packages/graphiql/src/components/GraphiQL.tsx b/packages/graphiql/src/components/GraphiQL.tsx
index be229f47e1c..117d1cd0fbf 100644
--- a/packages/graphiql/src/components/GraphiQL.tsx
+++ b/packages/graphiql/src/components/GraphiQL.tsx
@@ -531,7 +531,9 @@ export class GraphiQL extends React.Component<GraphiQLProps, GraphiQLState> {
     // Utility for keeping CodeMirror correctly sized.
     this.codeMirrorSizer = new CodeMirrorSizer();
 
-    global.g = this;
+    if (global) {
+      global.g = this;
+    }
   }
   UNSAFE_componentWillMount() {
     this.componentIsMounted = false;