diff --git a/src/encoding/binary/binary.go b/src/encoding/binary/binary.go
index 22fd7f2a80..85b3bc2295 100644
--- a/src/encoding/binary/binary.go
+++ b/src/encoding/binary/binary.go
@@ -665,6 +665,8 @@ func intDataSize(data interface{}) int {
 	switch data := data.(type) {
 	case bool, int8, uint8, *bool, *int8, *uint8:
 		return 1
+	case []bool:
+		return len(data)
 	case []int8:
 		return len(data)
 	case []uint8: