diff --git a/postgres-protocol/Cargo.toml b/postgres-protocol/Cargo.toml
index 6ab4c007..ef21a227 100644
--- a/postgres-protocol/Cargo.toml
+++ b/postgres-protocol/Cargo.toml
@@ -12,10 +12,10 @@ base64 = "0.9"
 byteorder = "1.0"
 bytes = "0.4"
 fallible-iterator = "0.1"
-generic-array = "0.11"
-hmac = "0.6"
-md5 = "0.3"
+generic-array = "0.12"
+hmac = "0.7"
+md5 = "0.4"
 memchr = "2.0"
 rand = "0.5"
-sha2 = "0.7"
+sha2 = "0.8"
 stringprep = "0.1"