diff --git a/include/openssl/ec.h b/include/openssl/ec.h
index 8b1abcebb7..f59b4f9288 100644
--- a/include/openssl/ec.h
+++ b/include/openssl/ec.h
@@ -915,10 +915,10 @@ int i2d_ECPKParameters(const EC_GROUP *, unsigned char **out);
 #  define i2d_ECPKParameters_bio(bp,x) \
     ASN1_i2d_bio_of(EC_GROUP, i2d_ECPKParameters, bp, x)
 #  define d2i_ECPKParameters_fp(fp,x) \
-    (EC_GROUP *)ASN1_d2i_fp(NULL, (char *(*)())d2i_ECPKParameters, (fp), \
-                            (unsigned char **)(x))
+    (EC_GROUP *)ASN1_d2i_fp(NULL, (d2i_of_void *)d2i_ECPKParameters, (fp), \
+                            (void **)(x))
 #  define i2d_ECPKParameters_fp(fp,x) \
-    ASN1_i2d_fp(i2d_ECPKParameters,(fp), (unsigned char *)(x))
+    ASN1_i2d_fp((i2d_of_void *)i2d_ECPKParameters, (fp), (void *)(x))
 
 #  ifndef OPENSSL_NO_DEPRECATED_3_0
 OSSL_DEPRECATEDIN_3_0 int ECPKParameters_print(BIO *bp, const EC_GROUP *x,