diff --git a/crypto/asn1/a_i2d_fp.c b/crypto/asn1/a_i2d_fp.c
index 8a6ce256..74ded78b 100644
--- a/crypto/asn1/a_i2d_fp.c
+++ b/crypto/asn1/a_i2d_fp.c
@@ -76,7 +76,7 @@ int ASN1_i2d_fp(i2d_of_void *i2d, FILE *out, void *x)
         return(ret);
         }
 
-int ASN1_i2d_bio(i2d_of_void *i2d, BIO *out, unsigned char *x)
+int ASN1_i2d_bio(i2d_of_void *i2d, BIO *out, void *x)
 	{
 	char *b;
 	unsigned char *p;
diff --git a/include/openssl/asn1.h b/include/openssl/asn1.h
index 401532ab..043524d1 100644
--- a/include/openssl/asn1.h
+++ b/include/openssl/asn1.h
@@ -949,7 +949,7 @@ OPENSSL_EXPORT void *ASN1_d2i_bio(void *(*xnew)(void), d2i_of_void *d2i, BIO *in
 			  CHECKED_PPTR_OF(type, x)))
 
 OPENSSL_EXPORT void *ASN1_item_d2i_bio(const ASN1_ITEM *it, BIO *in, void *x);
-OPENSSL_EXPORT int ASN1_i2d_bio(i2d_of_void *i2d,BIO *out, unsigned char *x);
+OPENSSL_EXPORT int ASN1_i2d_bio(i2d_of_void *i2d,BIO *out, void *x);
 
 #define ASN1_i2d_bio_of(type,i2d,out,x) \
     (ASN1_i2d_bio(CHECKED_I2D_OF(type, i2d), \