diff --git a/.appveyor.yml b/.appveyor.yml
index 1ba8953..bb8e93a 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -22,7 +22,7 @@ install:
   - curl -sSf -o rustup-init.exe https://win.rustup.rs
   - rustup-init.exe -y --default-host %TARGET% --default-toolchain none --no-modify-path
   - rustup --version
-  - rustup install beta-%TARGET% 1.34.2-%TARGET%
+  - rustup install beta-%TARGET% 1.39.0-%TARGET%
   - rustup component add --toolchain beta-%TARGET% rustfmt clippy
 
 build: false
@@ -41,7 +41,7 @@ test_script:
   - cargo +beta-%TARGET% check --all-targets --features fail-on-warnings
   - cargo +beta-%TARGET% test --release --features "fail-on-warnings az f16 serde"
   - cargo +beta-%TARGET% fmt -- --check
-  - cargo +1.34.2-%TARGET% test --lib --features "fail-on-warnings az f16 serde"
+  - cargo +1.39.0-%TARGET% test --lib --features "fail-on-warnings az f16 serde"
 
 after_test:
   - C:\msys64\usr\bin\bash -c "if [ -d ""$USERPROFILE/.cargo/registry/cache"" ]; then cd ""$USERPROFILE/.cargo/registry""; /c/msys64/usr/bin/find cache -name \*.crate; fi"
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2193fbd..5e23b14 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -8,7 +8,7 @@
 before_script:
   - getconf LONG_BIT
   - rustup --version
-  - rustup install beta-$TARGET 1.34.2-$TARGET
+  - rustup install beta-$TARGET 1.39.0-$TARGET
   - rustup component add --toolchain beta-$TARGET rustfmt clippy
   - if [ -d cargo/registry/cache ]; then rm -rf $CARGO_HOME/registry/cache; mkdir -p $CARGO_HOME/registry; cp -R cargo/registry/cache $CARGO_HOME/registry/; echo Copied registry/cache; fi
   - if [ -d $CARGO_HOME/registry/cache ]; then (cd $CARGO_HOME/registry; find cache -name \*.crate) fi
@@ -39,8 +39,8 @@ x86_64-gnulinux:
   - cargo +beta-$TARGET test --features "fail-on-warnings az f16 serde"
   - cargo +beta-$TARGET test --release --features "fail-on-warnings az f16 serde"
   - cargo +beta-$TARGET fmt -- --check
-  - cargo +1.34.2-$TARGET test --lib --features "fail-on-warnings az f16 serde"
-  - cargo +1.34.2-$TARGET test --release --lib --features "fail-on-warnings az f16 serde"
+  - cargo +1.39.0-$TARGET test --lib --features "fail-on-warnings az f16 serde"
+  - cargo +1.39.0-$TARGET test --release --lib --features "fail-on-warnings az f16 serde"
 
 i686-gnulinux:
   image: i386/rust:1
@@ -62,5 +62,5 @@ i686-gnulinux:
   - cargo +beta-$TARGET test --features "fail-on-warnings f16 serde"
   - cargo +beta-$TARGET test --release --features "fail-on-warnings az f16 serde"
   - cargo +beta-$TARGET fmt -- --check
-  - cargo +1.34.2-$TARGET test --lib --features "fail-on-warnings az f16 serde"
-  - cargo +1.34.2-$TARGET test --release --lib --features "fail-on-warnings az f16 serde"
+  - cargo +1.39.0-$TARGET test --lib --features "fail-on-warnings az f16 serde"
+  - cargo +1.39.0-$TARGET test --release --lib --features "fail-on-warnings az f16 serde"
diff --git a/README.md b/README.md
index 7f5bdf7..2e793e8 100644
--- a/README.md
+++ b/README.md
@@ -68,8 +68,9 @@ The conversions supported cover the following cases.
 
 ## What’s new
 
-### Version 0.4.7 news (unreleased)
+### Version 0.5.0 news (unreleased)
 
+  * The *fixed* crate now requires rustc version 1.39.0 or later.
   * Support for Euclidean division by integers was added.
 
 ### Version 0.4.6 news (2019-10-16)
@@ -185,7 +186,7 @@ it in your crate, add it as a dependency inside [*Cargo.toml*]:
 fixed = "0.4.6"
 ```
 
-The *fixed* crate requires rustc version 1.34.0 or later.
+The *fixed* crate requires rustc version 1.39.0 or later.
 
 ## Optional features
 
diff --git a/RELEASES.md b/RELEASES.md
index f232ef5..e1ed31f 100644
--- a/RELEASES.md
+++ b/RELEASES.md
@@ -5,12 +5,13 @@ modification, are permitted in any medium without royalty provided the
 copyright notice and this notice are preserved. This file is offered
 as-is, without any warranty. -->
 
-Version 0.4.6 (2019-10-16)
+Version 0.5.0 (unreleased)
 ==========================
 
+  * The *fixed* crate now requires rustc version 1.39.0 or later.
   * Support for Euclidean division by integers was added.
 
-Version 0.4.7 (unreleased)
+Version 0.4.6 (2019-10-16)
 ==========================
 
   * Conversions to/from `bf16` are now provided when the `f16` option
diff --git a/src/lib.rs b/src/lib.rs
index f5942e2..ea14ab4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -140,7 +140,7 @@ it in your crate, add it as a dependency inside [*Cargo.toml*]:
 fixed = "0.4.6"
 ```
 
-The *fixed* crate requires rustc version 1.34.0 or later.
+The *fixed* crate requires rustc version 1.39.0 or later.
 
 ## Optional features