diff --git a/src/util/rand_xor.c b/src/util/rand_xor.c
index 31612d57660..b34b4e40bfa 100644
--- a/src/util/rand_xor.c
+++ b/src/util/rand_xor.c
@@ -41,7 +41,7 @@
  * to the public domain.
  */
 uint64_t
-rand_xorshift128plus(uint64_t *seed)
+rand_xorshift128plus(uint64_t seed[2])
 {
    uint64_t *s = seed;
 
@@ -55,7 +55,7 @@ rand_xorshift128plus(uint64_t *seed)
 }
 
 void
-s_rand_xorshift128plus(uint64_t *seed, bool randomised_seed)
+s_rand_xorshift128plus(uint64_t seed[2], bool randomised_seed)
 {
    if (!randomised_seed)
       goto fixed_seed;
diff --git a/src/util/rand_xor.h b/src/util/rand_xor.h
index 532d549bcda..b55598f228a 100644
--- a/src/util/rand_xor.h
+++ b/src/util/rand_xor.h
@@ -29,9 +29,9 @@
 #include <stdbool.h>
 
 uint64_t
-rand_xorshift128plus(uint64_t *seed);
+rand_xorshift128plus(uint64_t seed[2]);
 
 void
-s_rand_xorshift128plus(uint64_t *seed, bool randomised_seed);
+s_rand_xorshift128plus(uint64_t seed[2], bool randomised_seed);
 
 #endif /* RAND_XOR_H */