diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index 3144700..6c30853 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -137,7 +137,7 @@
     unsigned char dst_str[100];
     unsigned char output[100];
     aes_context ctx;
-    int iv_offset = 0;
+    size_t iv_offset = 0;
     int key_len;
 
     memset(key_str, 0x00, 100);
@@ -167,7 +167,7 @@
     unsigned char dst_str[100];
     unsigned char output[100];
     aes_context ctx;
-    int iv_offset = 0;
+    size_t iv_offset = 0;
     int key_len;
 
     memset(key_str, 0x00, 100);