diff --git a/requirements/constraints.txt b/requirements/constraints.txt
index c42d4ba8f..3fde6f1f4 100644
--- a/requirements/constraints.txt
+++ b/requirements/constraints.txt
@@ -337,3 +337,21 @@ inflection==0.3.1 \
 coreapi==2.3.3 \
     --hash=sha256:46145fcc1f7017c076a2ef684969b641d18a2991051fddec9458ad3f78ffc1cb \
     --hash=sha256:bf39d118d6d3e171f10df9ede5666f63ad80bba9a29a8ec17726a66cf52ee6f3
+sphinxcontrib-htmlhelp==1.0.1 \
+    --hash=sha256:e31c8271f5a8f04b620a500c0442a7d5cfc1a732fa5c10ec363f90fe72af0cb8 \
+    --hash=sha256:0d691ca8edf5995fbacfe69b191914256071a94cbad03c3688dca47385c9206c
+sphinxcontrib-applehelp==1.0.1 \
+    --hash=sha256:fb8dee85af95e5c30c91f10e7eb3c8967308518e0f7488a2828ef7bc191d0d5d \
+    --hash=sha256:edaa0ab2b2bc74403149cb0209d6775c96de797dfd5b5e2a71981309efab3897
+sphinxcontrib-qthelp==1.0.2 \
+    --hash=sha256:513049b93031beb1f57d4daea74068a4feb77aa5630f856fcff2e50de14e9a20 \
+    --hash=sha256:79465ce11ae5694ff165becda529a600c754f4bc459778778c7017374d4d406f
+sphinxcontrib-devhelp==1.0.1 \
+    --hash=sha256:9512ecb00a2b0821a146736b39f7aeb90759834b07e81e8cc23a9c70bacb9981 \
+    --hash=sha256:6c64b077937330a9128a4da74586e8c2130262f014689b4b89e2d08ee7294a34
+sphinxcontrib-jsmath==1.0.1 \
+    --hash=sha256:2ec2eaebfb78f3f2078e73666b1415417a116cc848b72e5172e596c871103178 \
+    --hash=sha256:a9925e4a4587247ed2191a22df5f6970656cb8ca2bd6284309578f2153e0c4b8
+sphinxcontrib-serializinghtml==1.1.1 \
+    --hash=sha256:01d9b2617d7e8ddf7a00cae091f08f9fa4db587cc160b493141ee56710810932 \
+    --hash=sha256:392187ac558863b8aff0d76dc78e0731fed58f3b06e2b00e22995dcdb630f213