Properly fix #3820

1 files changed, 7 insertions, 2 deletions

diff --git a/src/check_expr.cpp b/src/check_expr.cpp
index 27e750668..891378b99 100644
--- a/src/check_expr.cpp
+++ b/src/check_expr.cpp
@@ -4431,9 +4431,14 @@ gb_internal void convert_to_typed(CheckerContext *c, Operand *operand, Type *tar
 			defer (gb_string_free(type_str));
 
 			if (valid_count == 1) {
+				Type *new_type = t->Union.variants[first_success_index];
+				target_type = new_type;
+				if (is_type_union(new_type)) {
+					convert_to_typed(c, operand, new_type);
+					break;
+				}
+				operand->type = new_type;
 				operand->mode = Addressing_Value;
-				operand->type = t->Union.variants[first_success_index];
-				target_type = t->Union.variants[first_success_index];
 				break;
 			} else if (valid_count > 1) {
 				ERROR_BLOCK();