diff --git a/blake2b/blake2b.go b/blake2b/blake2b.go
index fa9e48e..ce62241 100644
--- a/blake2b/blake2b.go
+++ b/blake2b/blake2b.go
@@ -4,7 +4,7 @@
 
 // Package blake2b implements the BLAKE2b hash algorithm as
 // defined in RFC 7693.
-package blake2b
+package blake2b // import "golang.org/x/crypto/blake2b"
 
 import (
 	"encoding/binary"
diff --git a/blake2s/blake2s.go b/blake2s/blake2s.go
index 394c121..7e3fc4f 100644
--- a/blake2s/blake2s.go
+++ b/blake2s/blake2s.go
@@ -4,7 +4,7 @@
 
 // Package blake2s implements the BLAKE2s hash algorithm as
 // defined in RFC 7693.
-package blake2s
+package blake2s // import "golang.org/x/crypto/blake2s"
 
 import (
 	"encoding/binary"
diff --git a/chacha20poly1305/chacha20poly1305.go b/chacha20poly1305/chacha20poly1305.go
index eb6739a..3f0dcb9 100644
--- a/chacha20poly1305/chacha20poly1305.go
+++ b/chacha20poly1305/chacha20poly1305.go
@@ -3,7 +3,7 @@
 // license that can be found in the LICENSE file.
 
 // Package chacha20poly1305 implements the ChaCha20-Poly1305 AEAD as specified in RFC 7539.
-package chacha20poly1305
+package chacha20poly1305 // import "golang.org/x/crypto/chacha20poly1305"
 
 import (
 	"crypto/cipher"
diff --git a/cryptobyte/string.go b/cryptobyte/string.go
index b1215b3..6780336 100644
--- a/cryptobyte/string.go
+++ b/cryptobyte/string.go
@@ -5,7 +5,7 @@
 // Package cryptobyte implements building and parsing of byte strings for
 // DER-encoded ASN.1 and TLS messages. See the examples for the Builder and
 // String types to get started.
-package cryptobyte
+package cryptobyte // import "golang.org/x/crypto/cryptobyte"
 
 // String represents a string of bytes. It provides methods for parsing
 // fixed-length and length-prefixed values from it.