diff --git a/arm/curve25519/edwards25519_decode.S b/arm/curve25519/edwards25519_decode.S
index 9161768d..653689be 100644
--- a/arm/curve25519/edwards25519_decode.S
+++ b/arm/curve25519/edwards25519_decode.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as
diff --git a/arm/curve25519/edwards25519_decode_alt.S b/arm/curve25519/edwards25519_decode_alt.S
index c77a1917..a8e842f1 100644
--- a/arm/curve25519/edwards25519_decode_alt.S
+++ b/arm/curve25519/edwards25519_decode_alt.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as
diff --git a/include/s2n-bignum.h b/include/s2n-bignum.h
index 5a3eebea..5c3140b6 100644
--- a/include/s2n-bignum.h
+++ b/include/s2n-bignum.h
@@ -923,8 +923,8 @@ extern void curve25519_x25519base_byte_alt(uint8_t res[S2N_BIGNUM_STATIC 32],uin
 
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
-extern uint64_t edwards25519_decode(uint64_t z[S2N_BIGNUM_STATIC 8],uint8_t c[S2N_BIGNUM_STATIC 32]);
-extern uint64_t edwards25519_decode_alt(uint64_t z[S2N_BIGNUM_STATIC 8],uint8_t c[S2N_BIGNUM_STATIC 32]);
+extern uint64_t edwards25519_decode(uint64_t z[S2N_BIGNUM_STATIC 8], const uint8_t c[S2N_BIGNUM_STATIC 32]);
+extern uint64_t edwards25519_decode_alt(uint64_t z[S2N_BIGNUM_STATIC 8], const uint8_t c[S2N_BIGNUM_STATIC 32]);
 
 // Encode edwards25519 point into compressed form as 256-bit number
 // Input p[8]; output z[32] (bytes)
diff --git a/x86/curve25519/edwards25519_decode.S b/x86/curve25519/edwards25519_decode.S
index 175d8fa9..71d00422 100644
--- a/x86/curve25519/edwards25519_decode.S
+++ b/x86/curve25519/edwards25519_decode.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as
diff --git a/x86/curve25519/edwards25519_decode_alt.S b/x86/curve25519/edwards25519_decode_alt.S
index 5105d214..1af88396 100644
--- a/x86/curve25519/edwards25519_decode_alt.S
+++ b/x86/curve25519/edwards25519_decode_alt.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as
diff --git a/x86_att/curve25519/edwards25519_decode.S b/x86_att/curve25519/edwards25519_decode.S
index 05681925..24431ef5 100644
--- a/x86_att/curve25519/edwards25519_decode.S
+++ b/x86_att/curve25519/edwards25519_decode.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as
diff --git a/x86_att/curve25519/edwards25519_decode_alt.S b/x86_att/curve25519/edwards25519_decode_alt.S
index 570b2f90..c7854380 100644
--- a/x86_att/curve25519/edwards25519_decode_alt.S
+++ b/x86_att/curve25519/edwards25519_decode_alt.S
@@ -5,7 +5,7 @@
 // Decode compressed 256-bit form of edwards25519 point
 // Input c[32] (bytes); output function return and z[8]
 //
-// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8],uint8_t c[static 32]);
+// extern uint64_t edwards25519_decode_alt(uint64_t z[static 8], const uint8_t c[static 32]);
 //
 // This interprets the input byte string as a little-endian number
 // representing a point (x,y) on the edwards25519 curve, encoded as