diff --git a/requirements.in b/requirements.in
index 30937085..e490a0f5 100644
--- a/requirements.in
+++ b/requirements.in
@@ -23,6 +23,7 @@ xmltodict
 rangedict
 openpyxl
 gunicorn
+lxml<5
 
 # We have a fork of the bdd-tester repo, in order to add a single commit that
 # fixes the previous commit we were using, to work with the new pip resolver.
diff --git a/requirements.txt b/requirements.txt
index b6aeaa90..3d9263a5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -89,8 +89,9 @@ libcove==0.32.1
     #   libcoveweb
 libcoveweb==0.30.4
     # via -r requirements.in
-lxml==5.3.0
+lxml==4.9.4
     # via
+    #   -r requirements.in
     #   bdd-tester
     #   flattentool
     #   iatiutils
diff --git a/requirements_dev.txt b/requirements_dev.txt
index 8f26151d..7a3af938 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -158,7 +158,7 @@ libcoveweb==0.30.4
     # via -r requirements.txt
 libsass==0.23.0
     # via -r requirements_dev.in
-lxml==5.3.0
+lxml==4.9.4
     # via
     #   -r requirements.txt
     #   bdd-tester