diff --git a/erpcgen/src/CGenerator.cpp b/erpcgen/src/CGenerator.cpp
index 678be7f5..e7ff1b74 100644
--- a/erpcgen/src/CGenerator.cpp
+++ b/erpcgen/src/CGenerator.cpp
@@ -1968,7 +1968,7 @@ string CGenerator::getErrorReturnValue(FunctionBase *fn)
     }
 }
 
-string CGenerator::getFunctionServerCall(Function *fn, FunctionType *functionType, std::string prefix)
+string CGenerator::getFunctionServerCall(Function *fn, FunctionType *functionType, const std::string prefix)
 {
     string proto = "";
     if (!fn->getReturnType()->isVoid() && prefix.length() > 0)
diff --git a/erpcgen/src/CGenerator.hpp b/erpcgen/src/CGenerator.hpp
index 5e18beb0..bf1cef8a 100644
--- a/erpcgen/src/CGenerator.hpp
+++ b/erpcgen/src/CGenerator.hpp
@@ -467,7 +467,8 @@ class CGenerator : public Generator
      *
      * @return String prototype representation for given function.
      */
-    std::string getFunctionPrototype(Group *group, FunctionBase *fn, const std::string &interfaceName = "", const std::string &name = "", bool interfaceClass = false);
+    std::string getFunctionPrototype(Group *group, FunctionBase *fn, const std::string &interfaceName = "",
+                                     const std::string &name = "", bool interfaceClass = false);
 
     /*!
      * @brief This function return interface function representation called by server side.
@@ -477,7 +478,7 @@ class CGenerator : public Generator
      *
      * @return String representation for given function.
      */
-    std::string getFunctionServerCall(Function *fn, FunctionType *functionType = nullptr, std::string = "");
+    std::string getFunctionServerCall(Function *fn, FunctionType *functionType = nullptr, const std::string = "");
 
     /*!
      * @brief This function return name with guard.