diff --git a/gpgme/ChangeLog b/gpgme/ChangeLog
index ea8efb46..7d6c5af6 100644
--- a/gpgme/ChangeLog
+++ b/gpgme/ChangeLog
@@ -1,3 +1,8 @@
+2004-10-05  Marcus Brinkmann  <marcus@g10code.de>
+
+	* op-support.c (_gpgme_op_data_lookup): Use char pointer for
+	pointer arithmetic.
+
 2004-09-30  Marcus Brinkmann  <marcus@g10code.de>
 
 	* gpgme.m4: Implement the --api-version check.
diff --git a/gpgme/op-support.c b/gpgme/op-support.c
index e406af9c..be42e75c 100644
--- a/gpgme/op-support.c
+++ b/gpgme/op-support.c
@@ -50,7 +50,7 @@ _gpgme_op_data_lookup (gpgme_ctx_t ctx, ctx_op_data_id_t type, void **hook,
       data->next = ctx->op_data;
       data->type = type;
       data->cleanup = cleanup;
-      data->hook = ((void *) data) + sizeof (struct ctx_op_data);
+      data->hook = (void *) (((char *) data) + sizeof (struct ctx_op_data));
       ctx->op_data = data;
     }
   *hook = data->hook;