diff --git a/src/js/contentscript-end.js b/src/js/contentscript-end.js
index f7234d513..282056dcf 100644
--- a/src/js/contentscript-end.js
+++ b/src/js/contentscript-end.js
@@ -43,7 +43,7 @@ if ( window.location === null ) {
 }
 
 // This can happen
-if ( !vAPI ) {
+if ( typeof vAPI !== 'object' ) {
     //console.debug('contentscript-end.js > vAPI not found');
     return;
 }
diff --git a/src/js/contentscript-start.js b/src/js/contentscript-start.js
index 9b8131ccc..255f075ed 100644
--- a/src/js/contentscript-start.js
+++ b/src/js/contentscript-start.js
@@ -41,7 +41,7 @@ if ( document instanceof HTMLDocument === false ) {
 }
 
 // This can happen
-if ( !vAPI ) {
+if ( typeof vAPI !== 'object' ) {
     //console.debug('contentscript-start.js > vAPI not found');
     return;
 }