diff --git a/src/anbox/config.cpp b/src/anbox/config.cpp
index 4152b18..730ac95 100644
--- a/src/anbox/config.cpp
+++ b/src/anbox/config.cpp
@@ -24,28 +24,18 @@
 
 namespace fs = boost::filesystem;
 
-namespace {
-std::string prefix_dir_from_env(const std::string &path, const std::string &env_var) {
-    static auto snap_data_path = anbox::utils::get_env_value(env_var, "");
-    auto result = path;
-    if (!snap_data_path.empty())
-        result = anbox::utils::string_format("%s%s", snap_data_path, path);
-    return result;
-}
-}
-
 namespace anbox {
 namespace config {
 std::string in_snap_dir(const std::string &path) {
-    return prefix_dir_from_env(path, "SNAP");
+    return utils::prefix_dir_from_env(path, "SNAP");
 }
 
 std::string in_snap_data_dir(const std::string &path) {
-    return prefix_dir_from_env(path, "SNAP_COMMON");
+    return utils::prefix_dir_from_env(path, "SNAP_COMMON");
 }
 
 std::string in_snap_user_data_dir(const std::string &path) {
-    return prefix_dir_from_env(path, "SNAP_USER_COMMON");
+    return utils::prefix_dir_from_env(path, "SNAP_USER_COMMON");
 }
 
 std::string home_dir() {
diff --git a/src/anbox/utils.cpp b/src/anbox/utils.cpp
index ba602ec..5777bba 100644
--- a/src/anbox/utils.cpp
+++ b/src/anbox/utils.cpp
@@ -151,5 +151,14 @@ void ensure_paths(const std::vector<std::string> &paths) {
             fs::create_directories(fs::path(path));
     }
 }
+
+std::string prefix_dir_from_env(const std::string &path, const std::string &env_var) {
+    static auto snap_data_path = anbox::utils::get_env_value(env_var, "");
+    auto result = path;
+    if (!snap_data_path.empty())
+        result = anbox::utils::string_format("%s%s", snap_data_path, path);
+    return result;
+}
+
 } // namespace utils
 } // namespace anbox
diff --git a/src/anbox/utils.h b/src/anbox/utils.h
index 343872f..2c1c394 100644
--- a/src/anbox/utils.h
+++ b/src/anbox/utils.h
@@ -43,6 +43,8 @@ bool is_env_set(const std::string &name);
 
 void ensure_paths(const std::vector<std::string> &paths);
 
+std::string prefix_dir_from_env(const std::string &path, const std::string &env_var);
+
 template<typename... Types>
 static std::string string_format(const std::string& fmt_str, Types&&... args);
 } // namespace utils