diff --git a/test/build.info b/test/build.info
index 9d6a7824d8..b376d3c7ab 100644
--- a/test/build.info
+++ b/test/build.info
@@ -63,7 +63,7 @@ IF[{- !$disabled{tests} -}]
   INCLUDE[ecdhtest]=../include
   DEPEND[ecdhtest]=../libcrypto
 
-  SOURCE[gmdifftest]=gmdifftest.c
+  SOURCE[gmdifftest]=gmdifftest.c testutil.c test_main.c
   INCLUDE[gmdifftest]=../include
   DEPEND[gmdifftest]=../libcrypto
 
diff --git a/test/gmdifftest.c b/test/gmdifftest.c
index 73c910dd2f..462436ff48 100644
--- a/test/gmdifftest.c
+++ b/test/gmdifftest.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2015-2017 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the OpenSSL license (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
@@ -8,7 +8,9 @@
  */
 
 #include <openssl/crypto.h>
-#include <stdio.h>
+
+#include "test_main.h"
+#include "testutil.h"
 
 #define SECS_PER_DAY (24 * 60 * 60)
 
@@ -24,6 +26,7 @@ static int check_time(long offset)
     int off_day, off_sec;
     long toffset;
     time_t t1, t2;
+
     time(&t1);
 
     t2 = t1 + offset;
@@ -31,51 +34,32 @@ static int check_time(long offset)
     OPENSSL_gmtime(&t1, &tm1);
     o1 = tm1;
     OPENSSL_gmtime_adj(&tm1, 0, offset);
-    if ((tm1.tm_year != tm2.tm_year) ||
-        (tm1.tm_mon != tm2.tm_mon) ||
-        (tm1.tm_mday != tm2.tm_mday) ||
-        (tm1.tm_hour != tm2.tm_hour) ||
-        (tm1.tm_min != tm2.tm_min) || (tm1.tm_sec != tm2.tm_sec)) {
-        fprintf(stderr, "TIME ERROR!!\n");
-        fprintf(stderr, "Time1: %d/%d/%d, %d:%02d:%02d\n",
-                tm2.tm_mday, tm2.tm_mon + 1, tm2.tm_year + 1900,
-                tm2.tm_hour, tm2.tm_min, tm2.tm_sec);
-        fprintf(stderr, "Time2: %d/%d/%d, %d:%02d:%02d\n",
-                tm1.tm_mday, tm1.tm_mon + 1, tm1.tm_year + 1900,
-                tm1.tm_hour, tm1.tm_min, tm1.tm_sec);
+    if (!TEST_int_eq(tm1.tm_year, tm2.tm_year)
+        || !TEST_int_eq(tm1.tm_mon, tm2.tm_mon)
+        || !TEST_int_eq(tm1.tm_mday, tm2.tm_mday)
+        || !TEST_int_eq(tm1.tm_hour, tm2.tm_hour)
+        || !TEST_int_eq(tm1.tm_min, tm2.tm_min)
+        || !TEST_int_eq(tm1.tm_sec, tm2.tm_sec)
+        || !TEST_true(OPENSSL_gmtime_diff(&off_day, &off_sec, &o1, &tm1)))
         return 0;
-    }
-    if (!OPENSSL_gmtime_diff(&off_day, &off_sec, &o1, &tm1))
+    toffset = (long)off_day * SECS_PER_DAY + off_sec;
+    if (!TEST_long_eq(offset, toffset))
         return 0;
-    toffset = (long)off_day *SECS_PER_DAY + off_sec;
-    if (offset != toffset) {
-        fprintf(stderr, "TIME OFFSET ERROR!!\n");
-        fprintf(stderr, "Expected %ld, Got %ld (%d:%d)\n",
-                offset, toffset, off_day, off_sec);
-        return 0;
-    }
     return 1;
 }
 
-int main(int argc, char **argv)
+static int test_gmtime(int offset)
 {
-    long offset;
-    int fails;
-
-    if (sizeof(time_t) < 8) {
-        fprintf(stderr, "Skipping; time_t is less than 64-bits\n");
-        return 0;
-    }
-    for (fails = 0, offset = 0; offset < 1000000; offset++) {
-        if (!check_time(offset))
-            fails++;
-        if (!check_time(-offset))
-            fails++;
-        if (!check_time(offset * 1000))
-            fails++;
-        if (!check_time(-offset * 1000))
-            fails++;
-    }
-
-    return fails ? 1 : 0;
+    return check_time(offset) &&
+           check_time(-offset) &&
+           check_time(offset * 1000L) &&
+           check_time(-offset * 1000L);
+}
+
+void register_tests(void)
+{
+    if (sizeof(time_t) < 8)
+        TEST_info("Skipping; time_t is less than 64-bits");
+    else
+        ADD_ALL_TESTS(test_gmtime, 1000000);
 }