diff --git a/crypto/evp/evp.h b/crypto/evp/evp.h
index 4e4a667ab84d72f17f39fe981cdc485cebc00676..a1dd3da1bfd0d8af37eae3591bcadabb9a08fe8d 100644
--- a/crypto/evp/evp.h
+++ b/crypto/evp/evp.h
@@ -749,12 +749,12 @@ EVP_PKEY *	d2i_AutoPrivateKey(EVP_PKEY **a, unsigned char **pp,
 			long length);
 int		i2d_PrivateKey(EVP_PKEY *a, unsigned char **pp);
 
-int EVP_PKEY_copy_parameters(EVP_PKEY *to,EVP_PKEY *from);
-int EVP_PKEY_missing_parameters(EVP_PKEY *pkey);
+int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from);
+int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey);
 int EVP_PKEY_save_parameters(EVP_PKEY *pkey,int mode);
-int EVP_PKEY_cmp_parameters(EVP_PKEY *a,EVP_PKEY *b);
+int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b);
 
-int EVP_PKEY_cmp(EVP_PKEY *a,EVP_PKEY *b);
+int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b);
 
 int EVP_CIPHER_type(const EVP_CIPHER *ctx);
 
diff --git a/crypto/evp/p_lib.c b/crypto/evp/p_lib.c
index 8d23c0bd7200fa574c7ce4045549bc0b42839f01..74a007e29d5657223cbd68158067f0a7f33fbd81 100644
--- a/crypto/evp/p_lib.c
+++ b/crypto/evp/p_lib.c
@@ -150,7 +150,7 @@ int EVP_PKEY_save_parameters(EVP_PKEY *pkey, int mode)
 	return(0);
 	}
 
-int EVP_PKEY_copy_parameters(EVP_PKEY *to, EVP_PKEY *from)
+int EVP_PKEY_copy_parameters(EVP_PKEY *to, cpnst EVP_PKEY *from)
 	{
 	if (to->type != from->type)
 		{
@@ -198,7 +198,7 @@ err:
 	return(0);
 	}
 
-int EVP_PKEY_missing_parameters(EVP_PKEY *pkey)
+int EVP_PKEY_missing_parameters(const EVP_PKEY *pkey)
 	{
 #ifndef OPENSSL_NO_DSA
 	if (pkey->type == EVP_PKEY_DSA)
@@ -221,7 +221,7 @@ int EVP_PKEY_missing_parameters(EVP_PKEY *pkey)
 	return(0);
 	}
 
-int EVP_PKEY_cmp_parameters(EVP_PKEY *a, EVP_PKEY *b)
+int EVP_PKEY_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 	{
 #ifndef OPENSSL_NO_DSA
 	if ((a->type == EVP_PKEY_DSA) && (b->type == EVP_PKEY_DSA))
@@ -237,7 +237,7 @@ int EVP_PKEY_cmp_parameters(EVP_PKEY *a, EVP_PKEY *b)
 	return(-1);
 	}
 
-int EVP_PKEY_cmp(EVP_PKEY *a, EVP_PKEY *b)
+int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 	{
 	if (a->type != b->type)
 		return -1;