diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9c1c7c5..d989c9d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,10 @@
 # Python Buildpack Changelog
 
-# 151 (2019-03-)
+# 152 (2019-04-04)
+
+Python 3.7.3 now available.
+
+# 151 (2019-03-21)
 
 Python 3.5.7 and 3.4.10 now available on all Heroku stacks.
 
diff --git a/bin/default_pythons b/bin/default_pythons
index dbdb106..db3b6d0 100755
--- a/bin/default_pythons
+++ b/bin/default_pythons
@@ -2,7 +2,7 @@
 
 DEFAULT_PYTHON_VERSION="python-3.6.8"
 LATEST_36="python-3.6.8"
-LATEST_37="python-3.7.2"
+LATEST_37="python-3.7.3"
 LATEST_35="python-3.5.7"
 LATEST_34="python-3.4.10"
 LATEST_27="python-2.7.16"
diff --git a/builds/runtimes/python-3.7.3 b/builds/runtimes/python-3.7.3
new file mode 100755
index 0000000..4254362
--- /dev/null
+++ b/builds/runtimes/python-3.7.3
@@ -0,0 +1,32 @@
+#!/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/3.7.3/Python-3.7.3.tgz'
+curl -L $SOURCE_TARBALL | tar xz
+mv Python-3.7.3 src
+cd src
+
+./configure --prefix=$OUT_PREFIX --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 '{}' +
+
+# Remove spare /
+LOCATION=${OUT_PREFIX%?}
+
+ln $LOCATION/bin/python3 $LOCATION/bin/python
diff --git a/test/run b/test/run
index 2bc27cf..34f5fa5 100755
--- a/test/run
+++ b/test/run
@@ -2,7 +2,7 @@
 
 # Default Python Versions
 # shellcheck source=bin/default_pythons
-source "$BIN_DIR/default_pythons"
+source "bin/default_pythons"
 
 testAirflow() {
   export SLUGIFY_USES_TEXT_UNIDECODE="yes"
@@ -98,14 +98,19 @@ testPylibmc() {
 }
 
 testPythonDefault() {
+  updateVersion "pythonDefault" $DEFAULT_PYTHON_VERSION
   compile "pythonDefault"
   assertCaptured $DEFAULT_PYTHON_VERSION
+  assertNotCaptured "security update"
   assertCapturedSuccess
 }
 
 testPython2() {
+    updateVersion "python2" $LATEST_27
+    echo $LATEST_27 > "runtime.txt"
     compile "python2"
     assertCaptured $LATEST_27
+    assertNotCaptured "security update"
     assertCapturedSuccess
 }
 
@@ -123,9 +128,13 @@ testPython2_fail() {
 }
 
 testPython3_4() {
-  compile "python3_4"
-  assertCaptured $LATEST_34
-  assertCapturedSuccess
+  if [[ $STACK != "cedar-14" ]]; then
+    updateVersion "python3_4" $LATEST_34
+    compile "python3_4"
+    assertCaptured $LATEST_34
+    assertNotCaptured "security update"
+    assertCapturedSuccess
+  fi
 }
 
 testPython3_4_warn() {
@@ -146,9 +155,13 @@ testPython3_4_fail() {
 }
 
 testPython3_5() {
-  compile "python3_5"
-  assertCaptured $LATEST_35
-  assertCapturedSuccess
+  if [[ $STACK != "cedar-14" ]]; then
+    updateVersion "python3_5" $LATEST_35
+    compile "python3_5"
+    assertCaptured $LATEST_35
+    assertNotCaptured "security update"
+    assertCapturedSuccess
+  fi
 }
 
 testPython3_5_warn() {
@@ -169,8 +182,10 @@ testPython3_5_fail() {
 }
 
 testPython3_6() {
+  updateVersion "python3_6" $LATEST_36
   compile "python3_6"
   assertCaptured $LATEST_36
+  assertNotCaptured "security update"
   assertCapturedSuccess
 }
 
@@ -188,10 +203,12 @@ testPython3_6_fail() {
 }
 
 testPython3_7() {
+  updateVersion "python3_7" $LATEST_37
   compile "python3_7"
   if [[ $STACK = "cedar-14" ]]; then
     assertCapturedError
   else
+    assertNotCaptured "security update"
     assertCaptured $LATEST_37
     assertCapturedSuccess
   fi
diff --git a/test/utils b/test/utils
index 2de7b0c..1ddd24e 100644
--- a/test/utils
+++ b/test/utils
@@ -71,6 +71,11 @@ release()
   capture ${BUILDPACK_HOME}/bin/release ${BUILD_DIR}
 }
 
+updateVersion()
+{
+  echo "$2" > "test/fixtures/${1}/runtime.txt"
+}
+
 assertCapturedEquals()
 {
   assertEquals "$@" "$(cat ${STD_OUT})"