diff --git a/src/test/functionCall/functionCall.c b/src/test/functionCall/functionCall.c
index 68c9f63..b515c13 100644
--- a/src/test/functionCall/functionCall.c
+++ b/src/test/functionCall/functionCall.c
@@ -9,24 +9,28 @@ void printArgError(char* name, int expected, int result) {
   printf("ERROR:\t\t%s(<argumentList>)\tGOT: %d\tExpected: %d\n", name, result, expected);
 }
 
-void argumentTest(char* name, int expected, int result) {
+int argumentTest(char* name, int expected, int result) {
   if (expected == result) {
     printArgSuccess(name, expected, result);
+    return 0;
   } else {
     printArgError(name, expected, result);
+    return 1;
   }
 }
 
-void runFunctionCallTests () {
+int runFunctionCallTests () {
+  int failed = 0;
   printf("\nFunctionCallTests Tests \n");
-  argumentTest("arg1", 1, arg1(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg2", 2, arg2(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg3", 3, arg3(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg4", 4, arg4(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg5", 5, arg5(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg6", 6, arg6(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg7", 7, arg7(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg8", 8, arg8(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg9", 9, arg9(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
-  argumentTest("arg10", 10, arg10(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg1", 1, arg1(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg2", 2, arg2(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg3", 3, arg3(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg4", 4, arg4(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg5", 5, arg5(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg6", 6, arg6(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg7", 7, arg7(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg8", 8, arg8(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg9", 9, arg9(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  failed += argumentTest("arg10", 10, arg10(1, 2, 3, 4, 5, 6, 7, 8, 9, 10));
+  return failed;
 }
\ No newline at end of file
diff --git a/src/test/testCode.c b/src/test/testCode.c
index 9b55e27..865c775 100644
--- a/src/test/testCode.c
+++ b/src/test/testCode.c
@@ -1,4 +1,5 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include "tests.h"
 #include "testCode.h"
 
@@ -37,72 +38,81 @@ void printErrorOneArg(char* name, int x, int expected, int result) {
   printf("ERROR:\t\t%s(%d)\tGOT: %d\tExpected: %d\n", name, x, result, expected);
 }
 
-void testExpected(char* name, int x, int y, int expected, int result) {
+int testExpected(char* name, int x, int y, int expected, int result) {
   if (expected == result) {
     printSuccess(name, x, y, expected, result);
+    return 0;
   } else {
     printError(name, x, y, expected, result);
+    return 1;
   }
 }
 
-void test(char* name, int (*correctFunction)(int, int), int (*testFunction)(int, int), int x, int y) {
+int test(char* name, int (*correctFunction)(int, int), int (*testFunction)(int, int), int x, int y) {
   int expected = correctFunction(x, y);
   int result = testFunction(x, y);
-  testExpected(name, x, y, expected, result);
+  return testExpected(name, x, y, expected, result);
 }
 
-void testOneArg(char* name, int (*correctFunction)(int), int (*testFunction)(int), int x) {
+int testOneArg(char* name, int (*correctFunction)(int), int (*testFunction)(int), int x) {
   int expected = correctFunction(x);
   int result = testFunction(x);
   if (expected == result) {
     printSuccessOneArg(name, x, expected, result);
+    return 0;
   } else {
     printErrorOneArg(name, x, expected, result);
+    return 1;
   }
 }
 
 int main(){
+  int failed = 0;
   printf("\nAddition Tests \n");
-  test("add", cAdd, add, 0, 0);
-  test("add", cAdd, add, 1, 1);
-  test("add", cAdd, add, 2, 0);
-  test("add", cAdd, add, 1, 5);
-  test("add", cAdd, add, -1, -1);
+  failed += test("add", cAdd, add, 0, 0);
+  failed += test("add", cAdd, add, 1, 1);
+  failed += test("add", cAdd, add, 2, 0);
+  failed += test("add", cAdd, add, 1, 5);
+  failed += test("add", cAdd, add, -1, -1);
 
   printf("\nSubtraction Tests \n");
-  test("sub", cSub, sub, 0, 0);
-  test("sub", cSub, sub, 1, 1);
-  test("sub", cSub, sub, 2, 0);
-  test("sub", cSub, sub, 1, 5);
-  test("sub", cSub, sub, -1, -1);
+  failed += test("sub", cSub, sub, 0, 0);
+  failed += test("sub", cSub, sub, 1, 1);
+  failed += test("sub", cSub, sub, 2, 0);
+  failed += test("sub", cSub, sub, 1, 5);
+  failed += test("sub", cSub, sub, -1, -1);
 
   printf("\nMultiplication Tests \n");
-  test("mul", cMul, mul, 0, 0);
-  test("mul", cMul, mul, 1, 1);
-  test("mul", cMul, mul, 2, 0);
-  test("mul", cMul, mul, 1, 5);
-  test("mul", cMul, mul, -1, -1);
+  failed += test("mul", cMul, mul, 0, 0);
+  failed += test("mul", cMul, mul, 1, 1);
+  failed += test("mul", cMul, mul, 2, 0);
+  failed += test("mul", cMul, mul, 1, 5);
+  failed += test("mul", cMul, mul, -1, -1);
 
   printf("\nModulo Tests \n");
-  test("modulo", cModulo, modulo, 1, 1);
-  test("modulo", cModulo, modulo, 1, 5);
-  test("modulo", cModulo, modulo, -1, -1);
-  test("modulo", cModulo, modulo, 1337, 42);
+  failed +=  test("modulo", cModulo, modulo, 1, 1);
+  failed +=  test("modulo", cModulo, modulo, 1, 5);
+  failed +=  test("modulo", cModulo, modulo, -1, -1);
+  failed +=  test("modulo", cModulo, modulo, 1337, 42);
 
   printf("\nNegative Tests\n");
-  testOneArg("neg", cNeg, neg, 0);
-  testOneArg("neg", cNeg, neg, 1);
-  testOneArg("neg", cNeg, neg, -1);
+  failed += testOneArg("neg", cNeg, neg, 0);
+  failed += testOneArg("neg", cNeg, neg, 1);
+  failed += testOneArg("neg", cNeg, neg, -1);
 
   printf("\nIdentity Tests\n");
-  testOneArg("id", cId, id, 0);
-  testOneArg("id", cId, id, -1);
-  testOneArg("id", cId, id, 15);
+  failed +=  testOneArg("id", cId, id, 0);
+  failed +=  testOneArg("id", cId, id, -1);
+  failed +=  testOneArg("id", cId, id, 15);
 
   printf("\nFunction Argument Tests\n");
-  runFunctionCallTests();
+  failed += runFunctionCallTests();
 
+  printf("\n=== Failed Tests: %d\n", failed);
+  if (failed > 0) {
+    return EXIT_FAILURE;
+  }
 
-  return 0;
+  return EXIT_SUCCESS;
 }
   
\ No newline at end of file
diff --git a/src/test/tests.h b/src/test/tests.h
index b0374b9..112df7f 100644
--- a/src/test/tests.h
+++ b/src/test/tests.h
@@ -2,4 +2,4 @@
   Alle Test Module
 */
 
-void runFunctionCallTests ();
\ No newline at end of file
+int runFunctionCallTests ();
\ No newline at end of file