diff --git a/src/field_10x26_impl.h b/src/field_10x26_impl.h
index c4403fba22..390a2bcbc2 100644
--- a/src/field_10x26_impl.h
+++ b/src/field_10x26_impl.h
@@ -271,7 +271,7 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1
 #define VERIFY_BITS(x, n) do { } while(0)
 #endif
 
-SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint32_t *a, const uint32_t * SECP256K1_RESTRICT b, uint32_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_mul_inner(uint32_t *r, const uint32_t *a, const uint32_t * SECP256K1_RESTRICT b) {
     VERIFY_BITS(a[0], 30);
     VERIFY_BITS(a[1], 30);
     VERIFY_BITS(a[2], 30);
@@ -598,7 +598,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint32_t *a, const uin
     /* [r9 r8 r7 r6 r5 r4 r3 r2 r1 r0] = [p18 p17 p16 p15 p14 p13 p12 p11 p10 p9 p8 p7 p6 p5 p4 p3 p2 p1 p0] */
 }
 
-SECP256K1_INLINE static void secp256k1_fe_sqr_inner(const uint32_t *a, uint32_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_sqr_inner(uint32_t *r, const uint32_t *a) {
     VERIFY_BITS(a[0], 30);
     VERIFY_BITS(a[1], 30);
     VERIFY_BITS(a[2], 30);
@@ -879,7 +879,7 @@ static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const s
     secp256k1_fe_verify(b);
     VERIFY_CHECK(r != b);
 #endif
-    secp256k1_fe_mul_inner(a->n, b->n, r->n);
+    secp256k1_fe_mul_inner(r->n, a->n, b->n);
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 0;
@@ -892,7 +892,7 @@ static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
     VERIFY_CHECK(a->magnitude <= 8);
     secp256k1_fe_verify(a);
 #endif
-    secp256k1_fe_sqr_inner(a->n, r->n);
+    secp256k1_fe_sqr_inner(r->n, a->n);
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 0;
diff --git a/src/field_5x52_asm_impl.h b/src/field_5x52_asm_impl.h
index 23857cded3..af12fd30d2 100644
--- a/src/field_5x52_asm_impl.h
+++ b/src/field_5x52_asm_impl.h
@@ -14,7 +14,7 @@
 #ifndef _SECP256K1_FIELD_INNER5X52_IMPL_H_
 #define _SECP256K1_FIELD_INNER5X52_IMPL_H_
 
-SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t * SECP256K1_RESTRICT b, uint64_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_mul_inner(uint64_t *r, const uint64_t *a, const uint64_t * SECP256K1_RESTRICT b) {
 /**
  * Registers: rdx:rax = multiplication accumulator
  *            r9:r8   = c
@@ -284,7 +284,7 @@ __asm__ __volatile__(
 );
 }
 
-SECP256K1_INLINE static void secp256k1_fe_sqr_inner(const uint64_t *a, uint64_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_sqr_inner(uint64_t *r, const uint64_t *a) {
 /**
  * Registers: rdx:rax = multiplication accumulator
  *            r9:r8   = c
diff --git a/src/field_5x52_impl.h b/src/field_5x52_impl.h
index 75b210eaf6..4b833db362 100644
--- a/src/field_5x52_impl.h
+++ b/src/field_5x52_impl.h
@@ -255,7 +255,7 @@ static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const s
     secp256k1_fe_verify(b);
     VERIFY_CHECK(r != b);
 #endif
-    secp256k1_fe_mul_inner(a->n, b->n, r->n);
+    secp256k1_fe_mul_inner(r->n, a->n, b->n);
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 0;
@@ -268,7 +268,7 @@ static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
     VERIFY_CHECK(a->magnitude <= 8);
     secp256k1_fe_verify(a);
 #endif
-    secp256k1_fe_sqr_inner(a->n, r->n);
+    secp256k1_fe_sqr_inner(r->n, a->n);
 #ifdef VERIFY
     r->magnitude = 1;
     r->normalized = 0;
diff --git a/src/field_5x52_int128_impl.h b/src/field_5x52_int128_impl.h
index e552fb4319..ec631833cf 100644
--- a/src/field_5x52_int128_impl.h
+++ b/src/field_5x52_int128_impl.h
@@ -15,7 +15,7 @@
 #define VERIFY_BITS(x, n) do { } while(0)
 #endif
 
-SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uint64_t * SECP256K1_RESTRICT b, uint64_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_mul_inner(uint64_t *r, const uint64_t *a, const uint64_t * SECP256K1_RESTRICT b) {
     VERIFY_BITS(a[0], 56);
     VERIFY_BITS(a[1], 56);
     VERIFY_BITS(a[2], 56);
@@ -152,7 +152,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_inner(const uint64_t *a, const uin
     /* [r4 r3 r2 r1 r0] = [p8 p7 p6 p5 p4 p3 p2 p1 p0] */
 }
 
-SECP256K1_INLINE static void secp256k1_fe_sqr_inner(const uint64_t *a, uint64_t *r) {
+SECP256K1_INLINE static void secp256k1_fe_sqr_inner(uint64_t *r, const uint64_t *a) {
     VERIFY_BITS(a[0], 56);
     VERIFY_BITS(a[1], 56);
     VERIFY_BITS(a[2], 56);