diff --git a/tape/dynamic.go b/tape/dynamic.go
index 120eb50..31966b6 100644
--- a/tape/dynamic.go
+++ b/tape/dynamic.go
@@ -240,8 +240,16 @@ func decodeAnyOrError(decoder *Decoder, destination reflect.Value, tag Tag) (n i
 		if length > uint64(MaxStructureLength) {
 			return 0, ErrTooLong
 		}
+		lengthCast, err := Uint64ToIntSafe(length)
+		if err != nil { return n, err }
+		if isTypeAny(destination.Type()) {
+			// need a skeleton value if we are assigning to any.
+			value := reflect.MakeMapWithSize(reflect.TypeOf(dummyMap), lengthCast)
+			destination.Set(value)
+			destination = value
+		}
 		destination.Clear()
-		for _ = range length {
+		for _ = range lengthCast {
 			key, nn, err := decoder.ReadUint16()
 			n += nn; if err != nil { return n, err }
 			itemTag, nn, err := decoder.ReadTag()