diff --git a/ext/libxml/php_libxml2.def b/ext/libxml/php_libxml2.def
index f38d544b722..9557b3e34ef 100644
--- a/ext/libxml/php_libxml2.def
+++ b/ext/libxml/php_libxml2.def
@@ -1389,6 +1389,7 @@ xmlXPathCmpNodes
 xmlXPathCompareValues
 xmlXPathCompile
 xmlXPathCompiledEval
+xmlXPathCompiledEvalToBoolean
 xmlXPathConcatFunction
 xmlXPathContainsFunction
 xmlXPathContextSetCache