diff --git a/modules/juce_gui_extra/native/juce_WebBrowserComponent_linux.cpp b/modules/juce_gui_extra/native/juce_WebBrowserComponent_linux.cpp
index e8bb2f0e72..d71564f253 100644
--- a/modules/juce_gui_extra/native/juce_WebBrowserComponent_linux.cpp
+++ b/modules/juce_gui_extra/native/juce_WebBrowserComponent_linux.cpp
@@ -1332,10 +1332,9 @@ public:
         g.fillAll (Colours::white);
     }
 
-    void evaluateJavascript (const String& script, WebBrowserComponent::EvaluationCallback callback) override
+    void evaluateJavascript (const String& script, EvaluationCallback callback) override
     {
-        if (callback != nullptr)
-            evaluationCallbacks.push_back (std::move (callback));
+        evaluationCallbacks.push_back (std::move (callback));
 
         CommandReceiver::sendCommand (outChannel,
                                       "evaluateJavascript",
@@ -1346,7 +1345,7 @@ public:
     {
         const auto params = FromVar::convert<EvaluateJavascriptCallbackParams> (paramsIn);
 
-        if (! params.has_value() || evaluationCallbacks.size() == 0)
+        if (! params.has_value() || evaluationCallbacks.empty())
         {
             jassertfalse;
             return;
@@ -1368,7 +1367,7 @@ public:
         });
 
         auto& cb = evaluationCallbacks.front();
-        cb (result);
+        NullCheckedInvocation::invoke (cb, result);
         evaluationCallbacks.pop_front();
     }