diff --git a/application/requirements.txt b/application/requirements.txt
index 26a8dd49..b9005f1b 100644
--- a/application/requirements.txt
+++ b/application/requirements.txt
@@ -26,4 +26,4 @@ venusian==3.1.0
 watchdog==3.0.0
 WebOb==1.8.7
 zope.deprecation==5.0
-zope.interface==6.1
+zope.interface==6.4.post2
diff --git a/deployment/roles/briefkasten/files/requirements.txt b/deployment/roles/briefkasten/files/requirements.txt
index 637c47da..3c6f4be2 100644
--- a/deployment/roles/briefkasten/files/requirements.txt
+++ b/deployment/roles/briefkasten/files/requirements.txt
@@ -26,5 +26,5 @@ venusian==3.1.0
 watchdog==3.0.0
 WebOb==1.8.7
 zope.deprecation==5.0
-zope.interface==6.1
+zope.interface==6.4.post2
 briefkasten