diff --git a/src/mmoc/ir/expression.cpp b/src/mmoc/ir/expression.cpp
index c88a9099..4f23957e 100644
--- a/src/mmoc/ir/expression.cpp
+++ b/src/mmoc/ir/expression.cpp
@@ -28,6 +28,7 @@
 #include <util/model_config.h>
 #include <util/util.h>
 #include <util/visitors/expression_printer.h>
+#include <util/visitors/get_index_variables.h>
 #include <util/visitors/is_constant_index.h>
 #include <util/visitors/partial_eval_exp.h>
 
@@ -161,8 +162,8 @@ std::ostream& operator<<(std::ostream& out, const Expression& s)
   out << s.print();
   return out;
 }
-bool Expression::operator<(const Expression &other) const
-{                                          
+bool Expression::operator<(const Expression& other) const
+{
   std::stringstream cmp_this;
   std::stringstream cmp_other;
   cmp_this << *this;
@@ -170,5 +171,11 @@ bool Expression::operator<(const Expression &other) const
   return cmp_this.str() < cmp_other.str();
 }
 
+std::multimap<std::string, int> Expression::usedVariables() const
+{
+  GetIndexVariables used_variables;
+  return used_variables.apply(_exp);
+}
+
 }  // namespace IR
 }  // namespace MicroModelica
diff --git a/src/mmoc/ir/expression.h b/src/mmoc/ir/expression.h
index ed0aecfd..fb0ae688 100644
--- a/src/mmoc/ir/expression.h
+++ b/src/mmoc/ir/expression.h
@@ -43,10 +43,12 @@ class Expression {
   bool isScalar() const;
   list<Expression> indexes() const;
   static Expression generate(std::string var_name, std::vector<std::string> indices);
-  bool operator<(const Expression &other) const;
+  bool operator<(const Expression& other) const;
 
   friend std::ostream& operator<<(std::ostream& out, const Expression& s);
 
+  std::multimap<std::string, int> usedVariables() const;
+
   protected:
   std::vector<Expression> usageExps() const;