diff --git a/core/Cargo.toml b/core/Cargo.toml
index 649e8f73..ed577031 100644
--- a/core/Cargo.toml
+++ b/core/Cargo.toml
@@ -50,7 +50,7 @@ quickcheck = "0.9.0"
 wasm-timer = "0.2"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
 
 [features]
 default = ["secp256k1"]
diff --git a/protocols/floodsub/Cargo.toml b/protocols/floodsub/Cargo.toml
index d494b1f2..a08fcc49 100644
--- a/protocols/floodsub/Cargo.toml
+++ b/protocols/floodsub/Cargo.toml
@@ -21,4 +21,4 @@ rand = "0.7"
 smallvec = "1.6.1"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/protocols/gossipsub/Cargo.toml b/protocols/gossipsub/Cargo.toml
index a0ecbd5d..7f91804a 100644
--- a/protocols/gossipsub/Cargo.toml
+++ b/protocols/gossipsub/Cargo.toml
@@ -40,4 +40,4 @@ hex = "0.4.2"
 derive_builder = "0.10.0"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/protocols/identify/Cargo.toml b/protocols/identify/Cargo.toml
index 7a733373..b6bd5e4e 100644
--- a/protocols/identify/Cargo.toml
+++ b/protocols/identify/Cargo.toml
@@ -27,4 +27,4 @@ libp2p-noise = { path = "../../transports/noise" }
 libp2p-tcp = { path = "../../transports/tcp" }
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/protocols/kad/Cargo.toml b/protocols/kad/Cargo.toml
index 8e150779..5a9440cf 100644
--- a/protocols/kad/Cargo.toml
+++ b/protocols/kad/Cargo.toml
@@ -35,4 +35,4 @@ libp2p-yamux = { path = "../../muxers/yamux" }
 quickcheck = "0.9.0"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/protocols/relay/Cargo.toml b/protocols/relay/Cargo.toml
index a9e71711..e9451918 100644
--- a/protocols/relay/Cargo.toml
+++ b/protocols/relay/Cargo.toml
@@ -26,7 +26,7 @@ void = "1"
 wasm-timer = "0.2"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
 
 [dev-dependencies]
 env_logger = "0.9.0"
diff --git a/protocols/rendezvous/Cargo.toml b/protocols/rendezvous/Cargo.toml
index ac11088d..9f9d084f 100644
--- a/protocols/rendezvous/Cargo.toml
+++ b/protocols/rendezvous/Cargo.toml
@@ -32,4 +32,4 @@ rand = "0.8"
 tokio = { version = "1", features = [ "rt-multi-thread", "time", "macros", "sync", "process", "fs", "net" ] }
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/transports/noise/Cargo.toml b/transports/noise/Cargo.toml
index 66f7e7f5..68090242 100644
--- a/transports/noise/Cargo.toml
+++ b/transports/noise/Cargo.toml
@@ -35,4 +35,4 @@ quickcheck = "0.9.0"
 sodiumoxide = "0.2.5"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"
diff --git a/transports/plaintext/Cargo.toml b/transports/plaintext/Cargo.toml
index da7a7ef6..f09c60b6 100644
--- a/transports/plaintext/Cargo.toml
+++ b/transports/plaintext/Cargo.toml
@@ -25,4 +25,4 @@ quickcheck = "0.9.0"
 rand = "0.7"
 
 [build-dependencies]
-prost-build = "0.8"
+prost-build = "0.9"