diff --git a/homeassistant/package_constraints.txt b/homeassistant/package_constraints.txt
index 37649dcf42f..510d27ccccb 100644
--- a/homeassistant/package_constraints.txt
+++ b/homeassistant/package_constraints.txt
@@ -72,3 +72,8 @@ uuid==1000000000.0.0
 # Temporary constraint on pandas, to unblock 2021.7 releases
 # until we have fixed the wheels builds for newer versions.
 pandas==1.3.0
+
+# regex causes segfault with version 2021.8.27
+# https://bitbucket.org/mrabarnett/mrab-regex/issues/421/2021827-results-in-fatal-python-error
+# This is fixed in 2021.8.28
+regex==2021.8.28
diff --git a/script/gen_requirements_all.py b/script/gen_requirements_all.py
index c2c98191a85..f535958412d 100755
--- a/script/gen_requirements_all.py
+++ b/script/gen_requirements_all.py
@@ -93,6 +93,11 @@ uuid==1000000000.0.0
 # Temporary constraint on pandas, to unblock 2021.7 releases
 # until we have fixed the wheels builds for newer versions.
 pandas==1.3.0
+
+# regex causes segfault with version 2021.8.27
+# https://bitbucket.org/mrabarnett/mrab-regex/issues/421/2021827-results-in-fatal-python-error
+# This is fixed in 2021.8.28
+regex==2021.8.28
 """
 
 IGNORE_PRE_COMMIT_HOOK_ID = (