diff --git a/vlib/v/ast/table.v b/vlib/v/ast/table.v
index 30715d6d8d..cc8c8df274 100644
--- a/vlib/v/ast/table.v
+++ b/vlib/v/ast/table.v
@@ -1139,9 +1139,20 @@ pub fn (t &Table) sumtype_has_variant(parent Type, variant Type) bool {
 	parent_sym := t.get_type_symbol(parent)
 	if parent_sym.kind == .sum_type {
 		parent_info := parent_sym.info as SumType
-		for v in parent_info.variants {
-			if v.idx() == variant.idx() {
-				return true
+		var_sym := t.get_type_symbol(variant)
+		if var_sym.kind == .aggregate {
+			var_info := var_sym.info as Aggregate
+			for var_type in var_info.types {
+				if !t.sumtype_has_variant(parent, var_type) {
+					return false
+				}
+			}
+			return true
+		} else {
+			for v in parent_info.variants {
+				if v.idx() == variant.idx() {
+					return true
+				}
 			}
 		}
 	}
diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 94b8f439a0..cdd0aad7d7 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -1555,6 +1555,10 @@ pub fn (mut c Checker) infix_expr(mut node ast.InfixExpr) ast.Type {
 					}
 					return ast.void_type
 				}
+				if left_value_sym.kind == .sum_type
+					&& c.table.sumtype_has_variant(left_value_type, right_type) {
+					return ast.void_type
+				}
 				// []T << T or []T << []T
 				unwrapped_right_type := c.unwrap_generic(right_type)
 				if c.check_types(unwrapped_right_type, left_value_type)
diff --git a/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.out b/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.out
new file mode 100644
index 0000000000..14cfcb56c3
--- /dev/null
+++ b/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.out
@@ -0,0 +1,7 @@
+vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.vv:7:11: error: cannot use `(i8 | i16 | int | i64)` as type `SimpleInt` in return argument
+    5 |     match s {
+    6 |         i8, i16, int, i64 {
+    7 |             return s
+      |                    ^
+    8 |         }
+    9 |     }
diff --git a/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.vv b/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.vv
new file mode 100644
index 0000000000..0aea56cd10
--- /dev/null
+++ b/vlib/v/checker/tests/sumtype_mismatch_of_aggregate_err.vv
@@ -0,0 +1,13 @@
+type SimpleInt = i64 | int
+type SuperInt = i16 | i64 | i8 | int
+
+fn ret_super(s SuperInt) SimpleInt {
+	match s {
+		i8, i16, int, i64 {
+			return s
+		}
+	}
+}
+
+fn main() {
+}
diff --git a/vlib/v/tests/array_of_sumtype_append_aggregate_type_test.v b/vlib/v/tests/array_of_sumtype_append_aggregate_type_test.v
new file mode 100644
index 0000000000..efae04056b
--- /dev/null
+++ b/vlib/v/tests/array_of_sumtype_append_aggregate_type_test.v
@@ -0,0 +1,29 @@
+struct StructA {
+	value int
+}
+
+struct StructB {
+	value  int
+	offset int
+}
+
+type AB = StructA | StructB
+
+fn test_sumtype_array_append_aggregate_type() {
+	mut arr := []AB{}
+	arr << StructA{0}
+	arr << StructB{0, 1}
+
+	mut arr2 := []AB{}
+
+	for a_or_b in arr {
+		match a_or_b {
+			StructA, StructB {
+				arr2 << a_or_b
+			}
+		}
+	}
+
+	println(arr2)
+	assert arr2.len == 2
+}
diff --git a/vlib/v/tests/match_sumtype_var_aggregate_test.v b/vlib/v/tests/match_sumtype_var_aggregate_test.v
new file mode 100644
index 0000000000..9478b21dcf
--- /dev/null
+++ b/vlib/v/tests/match_sumtype_var_aggregate_test.v
@@ -0,0 +1,21 @@
+struct Foo {}
+
+struct Bar {}
+
+struct Baz {}
+
+type Sum = Bar | Baz | Foo
+
+fn foo(s Sum) Sum {
+	match s {
+		Foo, Bar { return s }
+		Baz { return Baz{} }
+	}
+}
+
+fn test_match_sumtype_var_aggregate() {
+	a := Foo{}
+	ret := foo(a)
+	println(ret)
+	assert '$ret' == 'Sum(Foo{})'
+}