diff --git a/src/hostkey.c b/src/hostkey.c
index 19c855d9..41b251b0 100644
--- a/src/hostkey.c
+++ b/src/hostkey.c
@@ -828,7 +828,7 @@ hostkey_method_ssh_ed25519_init(LIBSSH2_SESSION * session,
         return _libssh2_error(session, LIBSSH2_ERROR_PROTO, "could not create ED25519 public key");
     }
 
-    ctx = LIBSSH2_CALLOC(session, sizeof(libssh2_ed25519_ctx));
+    ctx = _libssh2_ed25519_new_ctx();
     if(ctx == NULL) {
         return _libssh2_error(session, LIBSSH2_ERROR_ALLOC, "could not alloc public/private key");
     }
diff --git a/src/openssl.c b/src/openssl.c
index 0f79fc27..64a2a12c 100644
--- a/src/openssl.c
+++ b/src/openssl.c
@@ -1590,7 +1590,7 @@ gen_publickey_from_ed25519_openssh_priv_data(LIBSSH2_SESSION *session,
         goto clean_exit;
     }
 
-    ctx = LIBSSH2_CALLOC(session, sizeof(libssh2_ed25519_ctx));
+    ctx = _libssh2_ed25519_new_ctx();
     if (ctx == NULL) {
         _libssh2_error(session, LIBSSH2_ERROR_ALLOC,
                        "Unable to allocate memory for ed25519 key");
diff --git a/src/openssl.h b/src/openssl.h
index fe497a9b..4cd7ffde 100644
--- a/src/openssl.h
+++ b/src/openssl.h
@@ -325,6 +325,7 @@ typedef struct {
 #define libssh2_ed25519_ctx libssh2_curve25519_keys
 #define libssh2_x25519_ctx libssh2_curve25519_keys
 
+#define _libssh2_ed25519_new_ctx() malloc(sizeof(libssh2_ed25519_ctx))
 #define _libssh2_ed25519_free(ctx) do { \
  if(ctx) { \
   if(ctx->public_key) EVP_PKEY_free(ctx->public_key); \