diff --git a/src/CTree.cpp b/src/CTree.cpp
index 7d89cf3..de16250 100644
--- a/src/CTree.cpp
+++ b/src/CTree.cpp
@@ -7,16 +7,10 @@
 */
 
 #include "CTree.hpp"
+#include "utils.hpp"
 
 InvalidNodeException::~InvalidNodeException() = default;
 
-std::string joinPaths(const std::string& prefix, const std::string& suffix)
-{
-    if (prefix.empty() || suffix.empty())
-        return prefix + suffix;
-    else
-        return prefix + '/' + suffix;
-}
 
 bool TreeNode::operator<(const TreeNode& b) const
 {
diff --git a/src/ast.hpp b/src/ast.hpp
index f55ab39..93127d5 100644
--- a/src/ast.hpp
+++ b/src/ast.hpp
@@ -14,6 +14,7 @@
 #include <vector>
 
 #include "CTree.hpp"
+#include "utils.hpp"
 namespace x3 = boost::spirit::x3;
 namespace ascii = boost::spirit::x3::ascii;
 
diff --git a/src/utils.cpp b/src/utils.cpp
new file mode 100644
index 0000000..38bfe7d
--- /dev/null
+++ b/src/utils.cpp
@@ -0,0 +1,16 @@
+/*
+ * Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
+ * Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
+ *
+ * Written by Václav Kubernát <kubervac@fit.cvut.cz>
+ *
+*/
+#include "utils.hpp"
+
+std::string joinPaths(const std::string& prefix, const std::string& suffix)
+{
+    if (prefix.empty() || suffix.empty())
+        return prefix + suffix;
+    else
+        return prefix + '/' + suffix;
+}
diff --git a/src/utils.hpp b/src/utils.hpp
new file mode 100644
index 0000000..54c455a
--- /dev/null
+++ b/src/utils.hpp
@@ -0,0 +1,10 @@
+/*
+ * Copyright (C) 2018 CESNET, https://photonics.cesnet.cz/
+ * Copyright (C) 2018 FIT CVUT, https://fit.cvut.cz/
+ *
+ * Written by Václav Kubernát <kubervac@fit.cvut.cz>
+ *
+*/
+#include <string>
+
+std::string joinPaths(const std::string& prefix, const std::string& suffix);