diff --git a/src/rtdisasm_test.c b/src/rtdisasm_test.c
index 37a0f22..2d4ed47 100644
--- a/src/rtdisasm_test.c
+++ b/src/rtdisasm_test.c
@@ -4,8 +4,34 @@
 extern void test_1();
 extern void test_1_end();
 
+// TEST 2 - CRC calculation function to put rtdisasm to test
+
+static unsigned int test_2(unsigned char *message)
+{
+    int i, j;
+    unsigned int byte, crc, mask;
+
+    i = 0;
+    crc = 0xFFFFFFFF;
+    while (message[i] != 0)
+    {
+        byte = message[i];
+        crc = crc ^ byte;
+        for (j = 7; j >= 0; j--)
+        {
+            mask = -(crc & 1);
+            crc = (crc >> 1) ^ (0xEDB88320 & mask);
+        }
+        i = i + 1;
+    }
+    __asm__("nop"); // TARGET
+    return ~crc;
+}
+static void test_2_end() {}
+
 int main()
 {
+    printf("== TEST 1 ==\n");
     size_t size = (uintptr_t)test_1_end - (uintptr_t)test_1;
     printf("size %lu\n", size);
     // int len = rtdisasm_analyze_single((const uint8_t*)test_1, size, NULL);
@@ -19,5 +45,11 @@ int main()
     printf("RT_TARGET_SYSENTER %d\n", rtdisasm_find_target((const uint8_t*)test_1, size, RT_TARGET_SYSENTER));
     printf("RT_TARGET_SYSCALL %d\n", rtdisasm_find_target((const uint8_t*)test_1, size, RT_TARGET_SYSCALL));
     
+    printf("== TEST 2 ==\n");
+    size = (uintptr_t)test_2_end - (uintptr_t)test_2;
+    printf("size %lu\n", size);
+    
+    printf("test2 %d\n", rtdisasm_find_target((const uint8_t*)test_2, size, RT_TARGET_NOP));
+
     return 0;
 }
\ No newline at end of file