diff --git a/postgres-protocol/Cargo.toml b/postgres-protocol/Cargo.toml
index ef21a227..72194ac7 100644
--- a/postgres-protocol/Cargo.toml
+++ b/postgres-protocol/Cargo.toml
@@ -14,7 +14,7 @@ bytes = "0.4"
 fallible-iterator = "0.1"
 generic-array = "0.12"
 hmac = "0.7"
-md5 = "0.4"
+md5 = "0.5"
 memchr = "2.0"
 rand = "0.5"
 sha2 = "0.8"