diff --git a/ChangeLog b/ChangeLog
index c0df7cc89..aba1ba251 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,6 @@
+* 0.5.2:
+- Updated PyYAML dependencies to >=4.2b1 for https://nvd.nist.gov/vuln/detail/CVE-2017-18342
+
 * 0.5.1:
 - Fix bug related to usage of private grpc._interceptor._ClientCallDetails class
 
diff --git a/setup.py b/setup.py
index 2f290ef24..f4361d1a4 100644
--- a/setup.py
+++ b/setup.py
@@ -20,7 +20,7 @@
     'enum34; python_version < "3.4"',
     'google-auth-oauthlib>=0.0.1,<1.0.0',
     'google-api-core[grpc] >= 1.1.0, < 2.0.0dev',
-    'PyYAML >= 3.11, < 4.0',
+    'PyYAML >=4.2b1, < 5.0',
 ]
 
 tests_require = [
@@ -33,7 +33,7 @@
 
 setup(
     name='google-ads',
-    version='0.5.1',
+    version='0.5.2',
     author='Google LLC',
     author_email='googleapis-packages@google.com',
     classifiers=[