diff --git a/test/test-ctl-fuzz.c b/test/test-ctl-fuzz.c
index 89a1c24..1e68c7e 100644
--- a/test/test-ctl-fuzz.c
+++ b/test/test-ctl-fuzz.c
@@ -38,8 +38,9 @@ int main(void) {
   uint64_t total_events = 0;
   uint64_t start_time, last_print_time, now, total_time;
   SOCKET sockets[NUM_SOCKETS];
-  int r;
   HANDLE epfd;
+  size_t i;
+  int r;
 
   r = init();
   check(r == 0);
@@ -47,7 +48,7 @@ int main(void) {
   epfd = epoll_create1(0);
   check(epfd != NULL);
 
-  for (size_t i = 0; i < NUM_SOCKETS; i++)
+  for (i = 0; i < NUM_SOCKETS; i++)
     sockets[i] = create_and_add_socket(epfd);
 
   start_time = GetTickCount64();
@@ -57,7 +58,7 @@ int main(void) {
     struct epoll_event ev_out[64];
     uint64_t count;
 
-    for (size_t i = 0; i < NUM_SOCKETS; i++) {
+    for (i = 0; i < NUM_SOCKETS; i++) {
       SOCKET sock = sockets[i];
       struct epoll_event ev_in;
 
diff --git a/test/test-multi-poll.c b/test/test-multi-poll.c
index 643b982..73f5287 100644
--- a/test/test-multi-poll.c
+++ b/test/test-multi-poll.c
@@ -90,6 +90,7 @@ int main(void) {
   HANDLE ports[PORT_COUNT];
   test_context_t contexts[PORT_COUNT][THREADS_PER_PORT];
   WSADATA wsa_data;
+  size_t i, j;
   int r;
 
   /* Initialize winsock. */
@@ -101,7 +102,7 @@ int main(void) {
 
   /* Create PORT_COUNT epoll ports which, will be polled by THREADS_PER_PORT
    * threads. */
-  for (size_t i = 0; i < array_count(contexts); i++) {
+  for (i = 0; i < array_count(contexts); i++) {
     HANDLE port;
     struct epoll_event ev;
 
@@ -117,7 +118,7 @@ int main(void) {
     check(r == 0);
 
     /* Start THREADS_PER_PORT threads which will all poll the port. */
-    for (size_t j = 0; j < array_count(contexts[i]); j++) {
+    for (j = 0; j < array_count(contexts[i]); j++) {
       test_context_t* context = &contexts[i][j];
       HANDLE thread;
 
@@ -141,8 +142,8 @@ int main(void) {
   send_message(send_sock, LISTEN_PORT);
 
   /* Wait for all threads to exit and clean up after them. */
-  for (size_t i = 0; i < array_count(contexts); i++) {
-    for (size_t j = 0; j < array_count(contexts[i]); j++) {
+  for (i = 0; i < array_count(contexts); i++) {
+    for (j = 0; j < array_count(contexts[i]); j++) {
       HANDLE thread = contexts[i][j].thread;
       DWORD wr = WaitForSingleObject(thread, INFINITE);
       check(wr == WAIT_OBJECT_0);
@@ -151,7 +152,7 @@ int main(void) {
   }
 
   /* Close all epoll ports. */
-  for (size_t i = 0; i < array_count(ports); i++) {
+  for (i = 0; i < array_count(ports); i++) {
     HANDLE port = ports[i];
     r = epoll_close(port);
     check(r == 0);
diff --git a/test/test-reflock.c b/test/test-reflock.c
index 3526f58..e342518 100644
--- a/test/test-reflock.c
+++ b/test/test-reflock.c
@@ -70,10 +70,11 @@ static void destroy_reflock(test_context_t* context) {
 static void run_test_iteration(void) {
   test_context_t context;
   HANDLE threads[THREAD_COUNT];
+  size_t i;
 
   init_context(&context);
 
-  for (size_t i = 0; i < array_count(threads); i++) {
+  for (i = 0; i < array_count(threads); i++) {
     HANDLE thread =
         (HANDLE) _beginthreadex(NULL, 0, test_thread, &context, 0, NULL);
     check(thread != INVALID_HANDLE_VALUE);
@@ -84,7 +85,7 @@ static void run_test_iteration(void) {
 
   destroy_reflock(&context);
 
-  for (size_t i = 0; i < array_count(threads); i++) {
+  for (i = 0; i < array_count(threads); i++) {
     HANDLE thread = threads[i];
     DWORD wr = WaitForSingleObject(thread, INFINITE);
     check(wr == WAIT_OBJECT_0);
@@ -93,10 +94,12 @@ static void run_test_iteration(void) {
 }
 
 int main(void) {
+  int i;
+
   if (init() < 0)
     return 0;
 
-  for (int i = 0; i < TEST_ITERATIONS; i++) {
+  for (i = 0; i < TEST_ITERATIONS; i++) {
     printf("Iteration %d of %d\n", i + 1, TEST_ITERATIONS);
     run_test_iteration();
   }