diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 451aca9f..77e63738 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -56,7 +56,9 @@ jobs:
     - name: Setup PostgreSQL
       if: "!steps.release.outputs.is_release && matrix.os == 'macos-latest'"
       run: |
-        brew install postgresql
+        POSTGRES_FORMULA="postgresql@18"
+        brew install "$POSTGRES_FORMULA"
+        echo "$(brew --prefix "$POSTGRES_FORMULA")/bin" >> $GITHUB_PATH
 
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v6
@@ -86,7 +88,7 @@ jobs:
   test-postgres:
     strategy:
       matrix:
-        postgres-version: ["9.5", "9.6", "10", "11", "12", "13", "14", "15", "16", "17"]
+        postgres-version: ["9.5", "9.6", "10", "11", "12", "13", "14", "15", "16", "17", "18"]
 
     runs-on: ubuntu-latest
 
diff --git a/README.rst b/README.rst
index 70751b50..1a37296d 100644
--- a/README.rst
+++ b/README.rst
@@ -14,7 +14,7 @@ framework.  You can read more about asyncpg in an introductory
 `blog post <http://magic.io/blog/asyncpg-1m-rows-from-postgres-to-python/>`_.
 
 asyncpg requires Python 3.9 or later and is supported for PostgreSQL
-versions 9.5 to 17.  Other PostgreSQL versions or other databases
+versions 9.5 to 18.  Other PostgreSQL versions or other databases
 implementing the PostgreSQL protocol *may* work, but are not being
 actively tested.
 
diff --git a/docs/index.rst b/docs/index.rst
index bbad4397..5ca0bef0 100644
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -16,7 +16,7 @@ of PostgreSQL server binary protocol for use with Python's ``asyncio``
 framework.
 
 **asyncpg** requires Python 3.9 or later and is supported for PostgreSQL
-versions 9.5 to 17.  Other PostgreSQL versions or other databases implementing
+versions 9.5 to 18.  Other PostgreSQL versions or other databases implementing
 the PostgreSQL protocol *may* work, but are not being actively tested.
 
 Contents