diff --git a/vlib/v/ast/types.v b/vlib/v/ast/types.v
index b97656ac42..0cae9edaba 100644
--- a/vlib/v/ast/types.v
+++ b/vlib/v/ast/types.v
@@ -282,6 +282,9 @@ pub fn (t Type) debug() []string {
 	if t.has_flag(.optional) {
 		res << 'optional'
 	}
+	if t.has_flag(.result) {
+		res << 'result'
+	}
 	if t.has_flag(.variadic) {
 		res << 'variadic'
 	}
diff --git a/vlib/v/checker/str.v b/vlib/v/checker/str.v
index 0811585544..e51f45e103 100644
--- a/vlib/v/checker/str.v
+++ b/vlib/v/checker/str.v
@@ -32,7 +32,7 @@ pub fn (mut c Checker) get_default_fmt(ftyp ast.Type, typ ast.Type) u8 {
 		}
 		if ftyp in [ast.string_type, ast.bool_type]
 			|| sym.kind in [.enum_, .array, .array_fixed, .struct_, .map, .multi_return, .sum_type, .interface_, .none_]
-			|| ftyp.has_flag(.optional) || sym.has_method('str') {
+			|| ftyp.has_flag(.optional) || ftyp.has_flag(.result) || sym.has_method('str') {
 			return `s`
 		} else {
 			return `_`
diff --git a/vlib/v/gen/c/auto_str_methods.v b/vlib/v/gen/c/auto_str_methods.v
index a522ee26c6..cf9bd88418 100644
--- a/vlib/v/gen/c/auto_str_methods.v
+++ b/vlib/v/gen/c/auto_str_methods.v
@@ -67,6 +67,9 @@ fn (mut g Gen) get_str_fn(typ ast.Type) string {
 	if typ.has_flag(.optional) {
 		unwrapped.set_flag(.optional)
 	}
+	if typ.has_flag(.result) {
+		unwrapped.set_flag(.result)
+	}
 	styp := g.typ(unwrapped)
 	mut sym := g.table.sym(unwrapped)
 	mut str_fn_name := styp_to_str_fn_name(styp)