diff --git a/cue/testdata/builtins/closed.txtar b/cue/testdata/builtins/closed.txtar
index badd5f1..501576e 100644
--- a/cue/testdata/builtins/closed.txtar
+++ b/cue/testdata/builtins/closed.txtar
@@ -18,6 +18,30 @@
     x: syslog: xxx: {}
 }
 
+issue642: {
+    test: close({
+        a: _
+        b: x: _
+    } & {
+        [string]: y: _
+    })
+
+    test: a: x: _
+    test: b: x: _
+}
+
+// Issue 642
+withSubfields: {
+    test: close({
+        a: _
+        b: x: _
+        [string]: y: _
+    })
+
+    test: a: x: _
+    test: b: x: _
+}
+
 -- out/eval --
 Errors:
 b: field `x` not allowed:
@@ -29,13 +53,13 @@
 (_|_){
   // [eval]
   a: (#struct){
-    a: (#struct){
+    a: (struct){
       b: (int){ int }
     }
   }
   b: (_|_){
     // [eval]
-    a: (#struct){
+    a: (struct){
       b: (int){ int }
     }
     x: (_|_){
@@ -46,7 +70,7 @@
     }
   }
   c: (#struct){
-    a: (#struct){
+    a: (struct){
       b: (int){ int }
       c: (int){ int }
     }
@@ -118,6 +142,30 @@
     #Def: (#struct){
     }
   }
+  issue642: (struct){
+    test: (#struct){
+      a: (struct){
+        y: (_){ _ }
+        x: (_){ _ }
+      }
+      b: (struct){
+        x: (_){ _ }
+        y: (_){ _ }
+      }
+    }
+  }
+  withSubfields: (struct){
+    test: (#struct){
+      a: (struct){
+        y: (_){ _ }
+        x: (_){ _ }
+      }
+      b: (struct){
+        x: (_){ _ }
+        y: (_){ _ }
+      }
+    }
+  }
 }
 -- out/compile --
 --- in.cue
@@ -173,4 +221,47 @@
       }
     }
   }
+  issue642: {
+    test: close(({
+      a: _
+      b: {
+        x: _
+      }
+    } & {
+      [string]: {
+        y: _
+      }
+    }))
+    test: {
+      a: {
+        x: _
+      }
+    }
+    test: {
+      b: {
+        x: _
+      }
+    }
+  }
+  withSubfields: {
+    test: close({
+      a: _
+      b: {
+        x: _
+      }
+      [string]: {
+        y: _
+      }
+    })
+    test: {
+      a: {
+        x: _
+      }
+    }
+    test: {
+      b: {
+        x: _
+      }
+    }
+  }
 }
diff --git a/internal/core/adt/closed.go b/internal/core/adt/closed.go
index f68bc61..c385967 100644
--- a/internal/core/adt/closed.go
+++ b/internal/core/adt/closed.go
@@ -227,6 +227,9 @@
 
 func isClosed(v *Vertex) bool {
 	for _, s := range v.Structs {
+		if s.IsClosed {
+			return true
+		}
 		for c := s.closeInfo; c != nil; c = c.parent {
 			if c.isClosed() {
 				return true
diff --git a/internal/core/adt/eval.go b/internal/core/adt/eval.go
index 4c4b509..3053294 100644
--- a/internal/core/adt/eval.go
+++ b/internal/core/adt/eval.go
@@ -1299,7 +1299,6 @@
 			n.aStruct = x
 			n.aStructID = id
 			if m.NeedClose {
-				n.node.Closed = true // TODO: remove.
 				id = id.SpawnRef(x, IsDef(x), x)
 				id.IsClosed = true
 			}
diff --git a/internal/core/adt/optional.go b/internal/core/adt/optional.go
index 81c73c3..504d0f6 100644
--- a/internal/core/adt/optional.go
+++ b/internal/core/adt/optional.go
@@ -20,13 +20,16 @@
 func (o *StructInfo) MatchAndInsert(c *OpContext, arc *Vertex) {
 	env := o.Env
 
+	closeInfo := o.CloseInfo
+	closeInfo.IsClosed = false
+
 	// Match normal fields
 	matched := false
 outer:
 	for _, f := range o.Fields {
 		if f.Label == arc.Label {
 			for _, e := range f.Optional {
-				arc.AddConjunct(MakeConjunct(env, e, o.CloseInfo))
+				arc.AddConjunct(MakeConjunct(env, e, closeInfo))
 			}
 			matched = true
 			break outer
@@ -49,7 +52,7 @@
 		// }
 		if matchBulk(c, env, b, arc.Label) {
 			matched = true
-			arc.AddConjunct(MakeConjunct(&bulkEnv, b, o.CloseInfo))
+			arc.AddConjunct(MakeConjunct(&bulkEnv, b, closeInfo))
 		}
 	}
 	if matched {
@@ -62,7 +65,7 @@
 
 	// match others
 	for _, x := range o.Additional {
-		arc.AddConjunct(MakeConjunct(&addEnv, x, o.CloseInfo))
+		arc.AddConjunct(MakeConjunct(&addEnv, x, closeInfo))
 	}
 }