diff --git a/ir/Function.cpp b/ir/Function.cpp
index 95092e2..132b194 100644
--- a/ir/Function.cpp
+++ b/ir/Function.cpp
@@ -23,7 +23,7 @@ llvm::raw_ostream &operator<<(llvm::raw_ostream &s, const Function &func) {
     }
     if (func.isVariadic) {
         /* the C Iso require at least one argument in a variadic function, so the comma is fine */
-        s << ", varArgs: native.CVararg*";
+        s << ", " << func.getVarargsParameterName() << ": native.CVararg*";
     }
     s << "): "
       << func.retType
@@ -46,3 +46,21 @@ bool Function::usesType(const std::string &type) const {
 std::string Function::getName() const {
     return name;
 }
+
+std::string Function::getVarargsParameterName() const {
+    std::string parameterName = "varArgs";
+    int i = 0;
+    while (existParameterWithName(parameterName)) {
+        parameterName = "varArgs" + std::to_string(i++);
+    }
+    return parameterName;
+}
+
+bool Function::existParameterWithName(const std::string &parameterName) const {
+    for (const auto &parameter : parameters) {
+        if (parameter.getName() == parameterName) {
+            return true;
+        }
+    }
+    return false;
+}
diff --git a/ir/Function.h b/ir/Function.h
index b6e4718..fbe8323 100644
--- a/ir/Function.h
+++ b/ir/Function.h
@@ -24,6 +24,11 @@ class Function {
     std::string getName() const;
 
 private:
+
+    std::string getVarargsParameterName() const;
+
+    bool existParameterWithName(const std::string &parameterName) const;
+
     std::string name;
     std::vector<Parameter> parameters;
     std::string retType;
diff --git a/tests/samples/Function.h b/tests/samples/Function.h
index 4a848cb..7412a73 100644
--- a/tests/samples/Function.h
+++ b/tests/samples/Function.h
@@ -3,4 +3,4 @@ int void_arg(void);
 void one_arg(int a);
 void *two_args(float a, int b);
 void anonymous_args(float, int);
-double variadic_args(double a, void* b, ...);
+double variadic_args(double a, void* varArgs, ...);
diff --git a/tests/samples/Function.scala b/tests/samples/Function.scala
index 8457666..092586c 100644
--- a/tests/samples/Function.scala
+++ b/tests/samples/Function.scala
@@ -10,5 +10,5 @@ object Function {
   def one_arg(a: native.CInt): Unit = native.extern
   def two_args(a: native.CFloat, b: native.CInt): native.Ptr[Byte] = native.extern
   def anonymous_args(anonymous0: native.CFloat, anonymous1: native.CInt): Unit = native.extern
-  def variadic_args(a: native.CDouble, b: native.Ptr[Byte], varArgs: native.CVararg*): native.CDouble = native.extern
+  def variadic_args(a: native.CDouble, varArgs: native.Ptr[Byte], varArgs0: native.CVararg*): native.CDouble = native.extern
 }