Fix unused param warnings in test function
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index f74183d..da8c1e9 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -563,13 +563,21 @@
 /* BEGIN_CASE */
 void aes_misc_params( )
 {
+#if defined(MBEDTLS_CIPHER_MODE_CBC) || \
+    defined(MBEDTLS_CIPHER_MODE_XTS) || \
+    defined(MBEDTLS_CIPHER_MODE_CFB) || \
+    defined(MBEDTLS_CIPHER_MODE_OFB)
     mbedtls_aes_context aes_ctx;
+    const unsigned char in[16] = { 0 };
+    unsigned char out[16];
+#endif
 #if defined(MBEDTLS_CIPHER_MODE_XTS)
     mbedtls_aes_xts_context xts_ctx;
 #endif
-    const unsigned char in[16] = { 0 };
-    unsigned char out[16];
+#if defined(MBEDTLS_CIPHER_MODE_CFB) || \
+    defined(MBEDTLS_CIPHER_MODE_OFB)
     size_t size;
+#endif
 
     /* These calls accept NULL */
     TEST_VALID_PARAM( mbedtls_aes_free( NULL ) );