diff --git a/Cargo.lock b/Cargo.lock
index 82ff512f..d455267b 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1349,7 +1349,7 @@ dependencies = [
 [[package]]
 name = "tower"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "tower-buffer 0.3.0-alpha.2 (git+https://github.com/tower-rs/tower?branch=v0.3.x)",
@@ -1366,7 +1366,7 @@ dependencies = [
 [[package]]
 name = "tower-buffer"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1380,7 +1380,7 @@ dependencies = [
 [[package]]
 name = "tower-discover"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1390,12 +1390,12 @@ dependencies = [
 [[package]]
 name = "tower-layer"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 
 [[package]]
 name = "tower-limit"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1408,7 +1408,7 @@ dependencies = [
 [[package]]
 name = "tower-load"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1421,7 +1421,7 @@ dependencies = [
 [[package]]
 name = "tower-load-shed"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1441,7 +1441,7 @@ dependencies = [
 [[package]]
 name = "tower-retry"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1453,7 +1453,7 @@ dependencies = [
 [[package]]
 name = "tower-service"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 
 [[package]]
 name = "tower-service"
@@ -1463,7 +1463,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 [[package]]
 name = "tower-timeout"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "pin-project 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "tokio-timer 0.3.0-alpha.6 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1474,7 +1474,7 @@ dependencies = [
 [[package]]
 name = "tower-util"
 version = "0.3.0-alpha.2"
-source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#52dbdda23d17f6329be2bc5e4d918fcd3d6f69e5"
+source = "git+https://github.com/tower-rs/tower?branch=v0.3.x#51a374c564edc058c2b39449928d172de66e51dd"
 dependencies = [
  "futures-core-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "futures-util-preview 0.3.0-alpha.19 (registry+https://github.com/rust-lang/crates.io-index)",