diff --git a/src/classes/PFunction.cpp b/src/classes/PFunction.cpp
index cf402a5d..ef8bd0d2 100644
--- a/src/classes/PFunction.cpp
+++ b/src/classes/PFunction.cpp
@@ -655,7 +655,9 @@ void PFunction::EvalTreeForStringExpression(iter_t const& i)
       assert(i->children.size() == 2);
       EvalTreeForStringExpression(i->children.begin());
       fFuncString += " / ";
+      fFuncString += "(";
       EvalTreeForStringExpression(i->children.begin()+1);
+      fFuncString += ")";
     } else {
       assert(0);
     }