diff --git a/src/index.js b/src/index.js
index 2fa8b67..83a1b31 100644
--- a/src/index.js
+++ b/src/index.js
@@ -7,7 +7,7 @@ const ELEMENTS = 'a abbr address area article aside audio b base bdi bdo big blo
 
 const REACT_ELEMENT_TYPE = (typeof Symbol!=='undefined' && Symbol.for && Symbol.for('react.element')) || 0xeac7;
 
-const COMPONENT_WRAPPER_KEY = typeof Symbol!=='undefined' ? Symbol.for('__preactCompatWrapper') : '__preactCompatWrapper';
+const COMPONENT_WRAPPER_KEY = (typeof Symbol!=='undefined' && Symbol.for) ? Symbol.for('__preactCompatWrapper') : '__preactCompatWrapper';
 
 // don't autobind these methods since they already have guaranteed context.
 const AUTOBIND_BLACKLIST = {