diff --git a/third_party/fiat/curve25519.c b/third_party/fiat/curve25519.c
index e84073861350e80b2b38628630d56ddf846948fe..60237932ac2201ba485e2ff1ce07c0084b815c6d 100644
--- a/third_party/fiat/curve25519.c
+++ b/third_party/fiat/curve25519.c
@@ -3010,7 +3010,7 @@ void GFp_x25519_fe_neg(fe *f) {
   fe_carry(f, &t);
 }
 
-void GFp_x25519_fe_tobytes(uint8_t s[32], const fe *h) {
+void GFp_x25519_fe_tobytes(uint8_t *s, const fe *h) {
   fe_tobytes(s, h);
 }
 
diff --git a/third_party/fiat/internal.h b/third_party/fiat/internal.h
index 8f5f97a291c390ebd5e9ea2cc08b40db25c25688..f859ef836d22714e12de27da64b1127f6654c3cc 100644
--- a/third_party/fiat/internal.h
+++ b/third_party/fiat/internal.h
@@ -126,7 +126,7 @@ void GFp_x25519_ge_double_scalarmult_vartime(ge_p2 *r, const uint8_t *a,
                                              const ge_p3 *A,
                                              const uint8_t *b);
 int GFp_x25519_ge_frombytes_vartime(ge_p3 *h, const uint8_t *s);
-void GFp_x25519_ge_scalarmult_base(ge_p3 *h, const uint8_t a[32]);
+void GFp_x25519_ge_scalarmult_base(ge_p3 *h, const uint8_t *a);
 void GFp_x25519_sc_muladd(uint8_t *s, const uint8_t *a, const uint8_t *b,
                           const uint8_t *c);
 void GFp_x25519_sc_mask(uint8_t a[32]);