diff --git a/vlib/v/gen/cgen.v b/vlib/v/gen/cgen.v
index 89385cd166..0a5de1efc6 100644
--- a/vlib/v/gen/cgen.v
+++ b/vlib/v/gen/cgen.v
@@ -1433,8 +1433,9 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 	// int pos = *(int*)_t190.data;
 	mut gen_or := false
 	mut tmp_opt := ''
-	is_optional := g.pref.autofree && assign_stmt.op == .decl_assign && assign_stmt.left_types.len ==
-		1 && assign_stmt.right[0] is ast.CallExpr
+	is_optional := g.pref.autofree &&
+		(assign_stmt.op in [.decl_assign, .assign]) && assign_stmt.left_types.len == 1 && assign_stmt.right[0] is
+		ast.CallExpr
 	if is_optional {
 		// g.write('/* optional assignment */')
 		call_expr := assign_stmt.right[0] as ast.CallExpr
@@ -1726,7 +1727,7 @@ fn (mut g Gen) gen_assign_stmt(assign_stmt ast.AssignStmt) {
 				// `int pos = *(int)_t10.data;`
 				g.write('*($styp*)')
 				if g.pref.autofree {
-					g.write(tmp_opt + '.data/*FF*/')
+					g.write(tmp_opt + '.data/*FFz*/')
 					g.right_is_opt = false
 					g.is_assign_rhs = false
 					if g.inside_ternary == 0 && !assign_stmt.is_simple {
diff --git a/vlib/v/gen/fn.v b/vlib/v/gen/fn.v
index 6e49c70b15..39a2672ec9 100644
--- a/vlib/v/gen/fn.v
+++ b/vlib/v/gen/fn.v
@@ -15,11 +15,6 @@ fn (mut g Gen) gen_fn_decl(it ast.FnDecl, skip bool) {
 		// || it.no_body {
 		return
 	}
-	if g.pref.autofree {
-		defer {
-			// g.autofree_tmp_vars = []
-		}
-	}
 	// if g.fileis('vweb.v') {
 	// println('\ngen_fn_decl() $it.name $it.is_generic $g.cur_generic_type')
 	// }
@@ -661,12 +656,11 @@ fn (mut g Gen) autofree_call_pregen(node ast.CallExpr) {
 		// t := '_tt${g.tmp_count2}_arg_expr_${fn_name}_$i'
 		t := '_arg_expr_${fn_name}_$i'
 		// g.called_fn_name = name
-		// used := t in g.autofree_tmp_vars
 		used := scope.known_var(t)
 		mut s := ''
 		if used {
 			// This means this tmp var name was already used (the same function was called and
-			// `_arg_fnname_1` was already generated.
+			// `_arg_fnname_1` was already generated).
 			// We do not need to declare this variable again, so just generate `t = ...`
 			// instead of `string t = ...`, and we need to mark this variable as unused,
 			// so that it's freed after the call. (Used tmp arg vars are not freed to avoid double frees).
@@ -684,7 +678,6 @@ fn (mut g Gen) autofree_call_pregen(node ast.CallExpr) {
 				is_autofree_tmp: true
 			})
 			s = 'string $t = '
-			// g.autofree_tmp_vars << t
 		}
 		// g.expr(arg.expr)
 		s += g.write_expr_to_string(arg.expr)
@@ -707,7 +700,7 @@ fn (mut g Gen) autofree_call_postgen(node_pos int) {
 	if g.nr_vars_to_free <= 0 {
 		return
 	}
-	g.writeln('\n// strs_to_free3:')
+	// g.writeln('\n/* strs_to_free3: */')
 	/*
 	for s in g.strs_to_free {
 		g.writeln('string_free(&$s);')
diff --git a/vlib/v/tests/valgrind/1.strings_and_arrays.v b/vlib/v/tests/valgrind/1.strings_and_arrays.v
index 570d05552d..6d495864c3 100644
--- a/vlib/v/tests/valgrind/1.strings_and_arrays.v
+++ b/vlib/v/tests/valgrind/1.strings_and_arrays.v
@@ -119,6 +119,14 @@ fn optional_str() {
 		return
 	}
 	println(pos + 1)
+	//
+	mut p := 0
+	for {
+		p = opt('foo') or {
+			break
+		}
+		break
+	}
 }
 
 fn return_error_with_freed_expr() ?string {