diff --git a/Cargo.toml b/Cargo.toml
index b66ec2710..b23c6d655 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -35,7 +35,7 @@ path = "src/lib.rs"
 version = "0.4"
 
 [dependencies.protobuf]
-version = "3.2.0"
+version = "=3.6.0"
 
 [dependencies.serde]
 version = "1.0"
@@ -51,4 +51,4 @@ version = "0.11"
 version = "2.0.11"
 
 [build-dependencies.protobuf-codegen]
-version = "3.2.0"
+version = "=3.6.0"