diff --git a/vlib/v/gen/c/fn.v b/vlib/v/gen/c/fn.v
index 4554d739bf251f..774121456d9ed8 100644
--- a/vlib/v/gen/c/fn.v
+++ b/vlib/v/gen/c/fn.v
@@ -2719,6 +2719,8 @@ fn (mut g Gen) ref_or_deref_arg(arg ast.CallArg, expected_type ast.Type, lang as
 					if expected_type.has_flag(.option) {
 						g.expr_with_opt(arg.expr, arg_typ, expected_type)
 						return
+					} else if arg.expr is ast.Ident && arg.expr.language == .c {
+						g.write('(voidptr)')
 					} else {
 						g.write('(voidptr)&/*qq*/')
 					}