diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index a12a2523..cc7d0bdc 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -16,7 +16,7 @@ jobs:
           - nightly
           - beta
           - stable
-          - 1.40.0
+          - 1.56.0
         features:
           -
           - --features dummy_match_byte
@@ -35,10 +35,6 @@ jobs:
           toolchain: ${{ matrix.toolchain }}
           override: true
 
-      - name: Downgrade phf to a version compatible with the MSRV
-        run: cargo update --package phf --precise 0.10.1
-        if: matrix.toolchain == '1.40.0'
-
       - name: Cargo build
         run: cargo build ${{ matrix.features }}
 
diff --git a/Cargo.toml b/Cargo.toml
index 5819543c..0ab0f60f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,6 +11,7 @@ keywords = ["css", "syntax", "parser"]
 license = "MPL-2.0"
 build = "build.rs"
 edition = "2018"
+rust-version = "1.56"
 
 exclude = ["src/css-parsing-tests/**", "src/big-data-url.css"]
 
@@ -24,7 +25,7 @@ cssparser-macros = {path = "./macros", version = "0.6"}
 dtoa-short = "0.3"
 itoa = "1.0"
 matches = "0.1"
-phf = {version = ">=0.8,<=0.11", features = ["macros"]}
+phf = {version = "~0.9", features = ["macros"]}
 serde = {version = "1.0", optional = true}
 smallvec = "1.0"