diff --git a/.travis.yml b/.travis.yml
index bd1a2cb6..0300f51b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -11,7 +11,7 @@ matrix:
       env: TARGET=x86_64-apple-darwin
       cache: cargo
     - os: linux
-      rust: 1.27.0
+      rust: 1.31.0
       env: TARGET=x86_64-unknown-linux-gnu
       cache: cargo
     - os: linux
diff --git a/README.md b/README.md
index ec291121..fb9496bc 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ cargo build --release
 cp target/release/oxipng /usr/local/bin
 ```
 
-The current minimum supported Rust version is **1.27.0**. Oxipng may compile on earlier versions of Rust,
+The current minimum supported Rust version is **1.31.0**. Oxipng may compile on earlier versions of Rust,
 but there is no guarantee.
 
 Oxipng follows Semantic Versioning.
diff --git a/README.template.md b/README.template.md
index f7f3a1f4..da8e0934 100644
--- a/README.template.md
+++ b/README.template.md
@@ -26,7 +26,7 @@ cargo build --release
 cp target/release/oxipng /usr/local/bin
 ```
 
-The current minimum supported Rust version is **1.27.0**. Oxipng may compile on earlier versions of Rust,
+The current minimum supported Rust version is **1.31.0**. Oxipng may compile on earlier versions of Rust,
 but there is no guarantee.
 
 Oxipng follows Semantic Versioning.