diff --git a/docs/requirements.txt b/docs/requirements.txt
index 3b4a26a..cd17f87 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -140,18 +140,28 @@ python-stdnum==1.13 \
 pytz==2019.3 \
     --hash=sha256:1c557d7d0e871de1f5ccd5833f60fb2550652da6be2693c1e02300743d21500d \
     --hash=sha256:b02c06db6cf09c12dd25137e563b31700d3b80fcc4ad23abb7a315f2789819be
-pyyaml==5.3.1 \
-    --hash=sha256:74809a57b329d6cc0fdccee6318f44b9b8649961fa73144a98735b0aaf029f1f \
-    --hash=sha256:240097ff019d7c70a4922b6869d8a86407758333f02203e0fc6ff79c5dcede76 \
-    --hash=sha256:4f4b913ca1a7319b33cfb1369e91e50354d6f07a135f3b901aca02aa95940bd2 \
-    --hash=sha256:cc8955cfbfc7a115fa81d85284ee61147059a753344bc51098f3ccd69b0d7e0c \
-    --hash=sha256:7739fc0fa8205b3ee8808aea45e968bc90082c10aef6ea95e855e10abf4a37b2 \
-    --hash=sha256:69f00dca373f240f842b2931fb2c7e14ddbacd1397d57157a9b005a6a9942648 \
-    --hash=sha256:d13155f591e6fcc1ec3b30685d50bf0711574e2c0dfffd7644babf8b5102ca1a \
-    --hash=sha256:73f099454b799e05e5ab51423c7bcf361c58d3206fa7b0d555426b1f4d9a3eaf \
-    --hash=sha256:06a0d7ba600ce0b2d2fe2e78453a470b5a6e000a985dd4a4e54e436cc36b0e97 \
-    --hash=sha256:95f71d2af0ff4227885f7a6605c37fd53d3a106fcab511b8860ecca9fcf400ee \
-    --hash=sha256:b8eac752c5e14d3eca0e6dd9199cd627518cb5ec06add0de9d32baeee6fe645d
+pyyaml==5.4 \
+    --hash=sha256:f7a21e3d99aa3095ef0553e7ceba36fb693998fbb1226f1392ce33681047465f \
+    --hash=sha256:5e7ac4e0e79a53451dc2814f6876c2fa6f71452de1498bbe29c0b54b69a986f4 \
+    --hash=sha256:52bf0930903818e600ae6c2901f748bc4869c0c406056f679ab9614e5d21a166 \
+    --hash=sha256:a36a48a51e5471513a5aea920cdad84cbd56d70a5057cca3499a637496ea379c \
+    --hash=sha256:cc552b6434b90d9dbed6a4f13339625dc466fd82597119897e9489c953acbc22 \
+    --hash=sha256:0dc9f2eb2e3c97640928dec63fd8dc1dd91e6b6ed236bd5ac00332b99b5c2ff9 \
+    --hash=sha256:5a3f345acff76cad4aa9cb171ee76c590f37394186325d53d1aa25318b0d4a09 \
+    --hash=sha256:f3790156c606299ff499ec44db422f66f05a7363b39eb9d5b064f17bd7d7c47b \
+    --hash=sha256:124fd7c7bc1e95b1eafc60825f2daf67c73ce7b33f1194731240d24b0d1bf628 \
+    --hash=sha256:8b818b6c5a920cbe4203b5a6b14256f0e5244338244560da89b7b0f1313ea4b6 \
+    --hash=sha256:737bd70e454a284d456aa1fa71a0b429dd527bcbf52c5c33f7c8eee81ac16b89 \
+    --hash=sha256:7242790ab6c20316b8e7bb545be48d7ed36e26bbe279fd56f2c4a12510e60b4b \
+    --hash=sha256:cc547d3ead3754712223abb7b403f0a184e4c3eae18c9bb7fd15adef1597cc4b \
+    --hash=sha256:8635d53223b1f561b081ff4adecb828fd484b8efffe542edcfdff471997f7c39 \
+    --hash=sha256:26fcb33776857f4072601502d93e1a619f166c9c00befb52826e7b774efaa9db \
+    --hash=sha256:b2243dd033fd02c01212ad5c601dafb44fbb293065f430b0d3dbf03f3254d615 \
+    --hash=sha256:31ba07c54ef4a897758563e3a0fcc60077698df10180abe4b8165d9895c00ebf \
+    --hash=sha256:02c78d77281d8f8d07a255e57abdbf43b02257f59f50cc6b636937d68efa5dd0 \
+    --hash=sha256:fdc6b2cb4b19e431994f25a9160695cc59a4e861710cc6fc97161c5e845fc579 \
+    --hash=sha256:8bf38641b4713d77da19e91f8b5296b832e4db87338d6aeffe422d42f1ca896d \
+    --hash=sha256:3c49e39ac034fd64fd576d63bb4db53cda89b362768a67f07749d55f128ac18a
 regex==2020.4.4 \
     --hash=sha256:90742c6ff121a9c5b261b9b215cb476eea97df98ea82037ec8ac95d1be7a034f \
     --hash=sha256:24f4f4062eb16c5bbfff6a22312e8eab92c2c99c51a02e39b4eae54ce8255cd1 \