diff --git a/CHANGELOG.md b/CHANGELOG.md
index bfb248f..4ea834e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 # Master
 
+- Python 2.7.18, 3.5.9, 3.7.7 and 3.8.3 are now available (CPython).
+- PyPy 2.7 and 3.6, version 7.3.1 are now available (Note: PyPy support is in beta)
 - Docs: Fix explanation of runtime.txt generation when using pipenv
 - Bugfix: Correctly detect Python version when using a `python_version` of `3.8` in `Pipfile.lock`
 
diff --git a/README.md b/README.md
index dda1bfa..b7f2d6c 100644
--- a/README.md
+++ b/README.md
@@ -62,10 +62,10 @@ Specify a Python Runtime
 
 Supported runtime options include:
 
-- `python-3.8.2`
-- `python-3.7.6`
+- `python-3.8.3`
+- `python-3.7.7`
 - `python-3.6.10`
-- `python-2.7.17`
+- `python-2.7.18`
 
 ## Tests
 
diff --git a/bin/default_pythons b/bin/default_pythons
index 6c6d4a1..f016b86 100755
--- a/bin/default_pythons
+++ b/bin/default_pythons
@@ -1,14 +1,14 @@
 #!/usr/bin/env bash
 
 DEFAULT_PYTHON_VERSION="python-3.6.10"
-LATEST_38="python-3.8.2"
-LATEST_37="python-3.7.6"
+LATEST_38="python-3.8.3"
+LATEST_37="python-3.7.7"
 LATEST_36="python-3.6.10"
-LATEST_35="python-3.5.7"
+LATEST_35="python-3.5.9"
 LATEST_34="python-3.4.10"
-LATEST_27="python-2.7.17"
-PYPY_36="pypy3.6-7.2.0"
-PYPY_27="pypy2.7-7.2.0"
+LATEST_27="python-2.7.18"
+PYPY_36="pypy3.6-7.3.1"
+PYPY_27="pypy2.7-7.3.1"
 
 export DEFAULT_PYTHON_VERSION \
     LATEST_38 \
diff --git a/builds/heroku-18.Dockerfile b/builds/heroku-18.Dockerfile
index 80ad34d..9ee3080 100644
--- a/builds/heroku-18.Dockerfile
+++ b/builds/heroku-18.Dockerfile
@@ -1,4 +1,4 @@
-FROM heroku/heroku:18-build.v16
+FROM heroku/heroku:18-build
 
 WORKDIR /app
 ENV WORKSPACE_DIR="/app/builds" \
diff --git a/builds/runtimes/pypy2.7-7.3.1 b/builds/runtimes/pypy2.7-7.3.1
new file mode 100755
index 0000000..40761e9
--- /dev/null
+++ b/builds/runtimes/pypy2.7-7.3.1
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/pypy2.7
diff --git a/builds/runtimes/pypy3.6-7.3.1 b/builds/runtimes/pypy3.6-7.3.1
new file mode 100755
index 0000000..e429be8
--- /dev/null
+++ b/builds/runtimes/pypy3.6-7.3.1
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/pypy3.6
diff --git a/builds/runtimes/python-2.7.18 b/builds/runtimes/python-2.7.18
new file mode 100755
index 0000000..155e16d
--- /dev/null
+++ b/builds/runtimes/python-2.7.18
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+OUT_PREFIX=$1
+BIN_DIR="$(cd "$(dirname "$0")"/../.. || exit; pwd)/bin"
+export BIN_DIR
+
+# shellcheck source=bin/utils
+source "$BIN_DIR/steps/sqlite3"
+
+sqlite3_version
+echo "Setting up SQLite3 Headers for $SQLITE3_VERSION"
+sqlite3_install "$OUT_PREFIX" "$SQLITE3_VERSION" 1
+
+echo "Building Python…"
+SOURCE_TARBALL='https://python.org/ftp/python/2.7.18/Python-2.7.18.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-2.7.18 src
+cd src
+
+./configure --prefix=$OUT_PREFIX  --enable-unicode=ucs4 --with-ensurepip=no
+make
+make install
+
+# Remove unneeded test directories, similar to the official Docker Python images:
+# https://github.com/docker-library/python
+find "${OUT_PREFIX}" \( -type d -a \( -name test -o -name tests \) \) -exec rm -rf '{}' +
diff --git a/builds/runtimes/python-3.5.9 b/builds/runtimes/python-3.5.9
new file mode 100755
index 0000000..ad41723
--- /dev/null
+++ b/builds/runtimes/python-3.5.9
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/python3
diff --git a/builds/runtimes/python-3.7.7 b/builds/runtimes/python-3.7.7
new file mode 100755
index 0000000..ad41723
--- /dev/null
+++ b/builds/runtimes/python-3.7.7
@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/python/
+
+source $(dirname $0)/python3
diff --git a/builds/runtimes/python2 b/builds/runtimes/python2
old mode 100644
new mode 100755
diff --git a/test/fixtures/python2/runtime.txt b/test/fixtures/python2/runtime.txt
index b334cca..586b673 100644
--- a/test/fixtures/python2/runtime.txt
+++ b/test/fixtures/python2/runtime.txt
@@ -1 +1 @@
-python-2.7.17
+python-2.7.18
diff --git a/test/fixtures/python3_5/runtime.txt b/test/fixtures/python3_5/runtime.txt
index df4118a..435a592 100644
--- a/test/fixtures/python3_5/runtime.txt
+++ b/test/fixtures/python3_5/runtime.txt
@@ -1 +1 @@
-python-3.5.7
+python-3.5.9