diff --git a/requirements.txt b/requirements.txt
index 8a47cbe7b..fab09c373 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -251,8 +251,15 @@ pytz==2018.4 \
     --hash=sha256:65ae0c8101309c45772196b21b74c46b2e5d11b6275c45d251b150d5da334555 \
     --hash=sha256:c06425302f2cf668f1bba7a0a03f3c1d34d4ebeef2c72003da308b3947c7f749 \
     # via django, django-notifications-hq, fs, tzlocal
-pyyaml==4.1 \
-    --hash=sha256:a9b322285f419429402d5ce15e8f6d5c7a64f659eb87251af8b35c106f00a8e3 \
+pyyaml==3.12 \
+    --hash=sha256:16b20e970597e051997d90dc2cddc713a2876c47e3d92d59ee198700c5427736 \
+    --hash=sha256:3262c96a1ca437e7e4763e2843746588a965426550f3797a79fca9c6199c431f \
+    --hash=sha256:592766c6303207a20efc445587778322d7f73b161bd994f227adaa341ba212ab \
+    --hash=sha256:5ac82e411044fb129bae5cfbeb3ba626acb2af31a8d17d175004b70862a741a7 \
+    --hash=sha256:827dc04b8fa7d07c44de11fabbc888e627fa8293b695e0f99cb544fdfa1bf0d1 \
+    --hash=sha256:bc6bced57f826ca7cb5125a10b23fd0f2fff3b7c4701d64c439a300ce665fff8 \
+    --hash=sha256:c01b880ec30b5a6e6aa67b09a2fe3fb30473008c85cd6a67359a1b15ed6d83a4 \
+    --hash=sha256:e863072cdf4c72eebf179342c94e6989c67185842d9997960b3e69290b2fa269 \
     # via bandit, dparse, rtyaml
 requests-oauthlib==1.0.0 \
     --hash=sha256:8886bfec5ad7afb391ed5443b1f697c6f4ae98d0e5620839d8b4499c032ada3f \