diff --git a/cfg/wxwidgets.cfg b/cfg/wxwidgets.cfg
index 9e37f65eb..1aaceb8d9 100644
--- a/cfg/wxwidgets.cfg
+++ b/cfg/wxwidgets.cfg
@@ -14,4 +14,44 @@
       <not-uninit/>
     </arg>
   </function>
+  <!-- http://docs.wxwidgets.org/trunk/classwx_string.html#ace32756bab999f8aae9be0cf981fc449 -->
+  <!-- bool wxString::IsEmpty() -->
+  <function name="wxString::IsEmpty">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="bool"/>
+    <use-retval/>
+  </function>
+  <!-- http://docs.wxwidgets.org/trunk/classwx_string.html#ace32756bab999f8aae9be0cf981fc449 -->
+  <!-- bool wxString::IsNull() -->
+  <function name="wxString::IsNull">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="bool"/>
+    <use-retval/>
+  </function>
+  <!-- http://docs.wxwidgets.org/trunk/classwx_string.html#ace32756bab999f8aae9be0cf981fc449 -->
+  <!-- bool wxString::IsNumber() -->
+  <function name="wxString::IsNumber">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="bool"/>
+    <use-retval/>
+  </function>
+  <!-- http://docs.wxwidgets.org/trunk/classwx_string.html#ace32756bab999f8aae9be0cf981fc449 -->
+  <!-- bool wxString::IsAscii() -->
+  <function name="wxString::IsAscii">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="bool"/>
+    <use-retval/>
+  </function>
+  <!-- http://docs.wxwidgets.org/trunk/classwx_string.html#ace32756bab999f8aae9be0cf981fc449 -->
+  <!-- bool wxString::IsWord() -->
+  <function name="wxString::IsWord">
+    <noreturn>false</noreturn>
+    <leak-ignore/>
+    <returnValue type="bool"/>
+    <use-retval/>
+  </function>
 </def>