diff --git a/.travis.yml b/.travis.yml
index c49b965f554e..1cee9998d2e9 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,7 +15,7 @@ addons:
 services:
   - mysql
 before_install:
- # install sqlite3 version 3.24.0
+  # install sqlite3 version 3.24.0
   - |
     if [[ "$BACKEND" == sqlite ]]; then
       (sudo apt-get update) &&
@@ -87,7 +87,7 @@ matrix:
     env: RUSTFLAGS="--cap-lints=warn"
     script:
     - (cd diesel_compile_tests && cargo test)
-  - rust: 1.37.0
+  - rust: 1.40.0
     name: "Rustfmt && Clippy"
     script:
     - rustup component add rustfmt clippy
@@ -99,8 +99,8 @@ matrix:
     - SQLITE_DATABASE_URL=/tmp/test.db
     script:
     - (cd diesel_cli && cargo test --no-default-features --features "sqlite-bundled")
-  - rust: 1.37.0
-     name: "Minimal supported rust version == 1.37.0"
+  - rust: 1.40.0
+      name: "Minimal supported rust version == 1.40.0"
     script:
     - cargo check --all
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 57486dc073e8..76d73f13d7a4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -51,7 +51,7 @@ for Rust libraries in [RFC #1105](https://github.com/rust-lang/rfcs/blob/master/
   `Mysql::TypeMetadata`, you will need to take the new struct
   `MysqlTypeMetadata` instead.
 
-* The minimal officially supported rustc version is now 1.37.0
+* The minimal officially supported rustc version is now 1.40.0
 
 * The `RawValue` types for the `Mysql` and `Postgresql` backend where changed
   from `[u8]` to distinct opaque types. If you used the concrete `RawValue` type
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 801e7a586068..58ea22527ac4 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -186,7 +186,7 @@ jobs:
     - template: _build/install-rust.yml
       parameters:
         platform: Linux
-        rust_version: 1.36.0
+        rust_version: 1.40.0
     - bash: |
         sudo apt-get update &&
         sudo apt-get -y install libsqlite3-dev libpq-dev libmysqlclient-dev
@@ -233,11 +233,11 @@ jobs:
     - template: _build/install-rust.yml
       parameters:
         platform: Linux
-        rust_version: 1.36.0
+        rust_version: 1.40.0
     - bash: |
         sudo apt-get update &&
         sudo apt-get install libpq-dev libmysqlclient-dev
       displayName: Install build dependencies
     - bash: |
         cargo check --all
-      displayName: Check building with rust 1.36.0
+      displayName: Check building with rust 1.40.0
diff --git a/rust-toolchain b/rust-toolchain
index bf50e910e623..32b7211cb618 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.37.0
+1.40.0