diff --git a/bin/compile b/bin/compile
index f43ebf1..0466e8e 100755
--- a/bin/compile
+++ b/bin/compile
@@ -34,8 +34,8 @@ ENV_DIR=$3
 export BUILD_DIR CACHE_DIR ENV_DIR
 
 # Python defaults
-DEFAULT_PYTHON_VERSION="python-3.6.3"
-LATEST_3="python-3.6.3"
+DEFAULT_PYTHON_VERSION="python-3.6.4"
+LATEST_3="python-3.6.4"
 LATEST_2="python-2.7.14"
 
 DEFAULT_PYTHON_STACK="cedar-14"
diff --git a/builds/runtimes/python-3.6.4 b/builds/runtimes/python-3.6.4
old mode 100644
new mode 100755
diff --git a/test/run b/test/run
index 8c203d6..62e902f 100755
--- a/test/run
+++ b/test/run
@@ -12,7 +12,7 @@ testPipenvLock() {
 
 testPipenvVersion() {
   compile "pipenv-version"
-  assertCaptured "3.6.3"
+  assertCaptured "3.6.4"
   assertCapturedSuccess
 }
 
@@ -78,7 +78,7 @@ testPython2() {
 
 testPython3() {
   compile "python3"
-  assertCaptured "python-3.6.3"
+  assertCaptured "python-3.6.4"
   assertCapturedSuccess
 }