diff --git a/src/gtk/webview_webkit.cpp b/src/gtk/webview_webkit.cpp
index 5f82094ec4..ea0eb0d967 100644
--- a/src/gtk/webview_webkit.cpp
+++ b/src/gtk/webview_webkit.cpp
@@ -951,6 +951,9 @@ wxString wxWebViewWebKit::GetPageText() const
 
 bool wxWebViewWebKit::RunScript(const wxString& javascript, wxString* output)
 {
+    wxCHECK_MSG( m_web_view, false,
+        wxS("wxWebView must be created before calling RunScript()") );
+
     if ( output != NULL )
     {
         wxLogWarning(_("Retrieving JavaScript script output is not supported with WebKit v1"));
diff --git a/src/gtk/webview_webkit2.cpp b/src/gtk/webview_webkit2.cpp
index ebc67fcb85..a8c8cb1280 100644
--- a/src/gtk/webview_webkit2.cpp
+++ b/src/gtk/webview_webkit2.cpp
@@ -1172,6 +1172,9 @@ bool wxWebViewWebKit::RunScriptSync(const wxString& javascript, wxString* output
 
 bool wxWebViewWebKit::RunScript(const wxString& javascript, wxString* output)
 {
+    wxCHECK_MSG( m_web_view, false,
+        wxS("wxWebView must be created before calling RunScript()") );
+
     wxJSScriptWrapper wrapJS(javascript, &m_runScriptCount);
 
     wxString result;