diff --git a/ocis-phoenix/pkg/service/v0/service.go b/ocis-phoenix/pkg/service/v0/service.go
index 1f426af338..eea57c84a2 100644
--- a/ocis-phoenix/pkg/service/v0/service.go
+++ b/ocis-phoenix/pkg/service/v0/service.go
@@ -169,7 +169,7 @@ func (p Phoenix) Static(ttl int) http.HandlerFunc {
 			return
 		}
 
-		w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%s", strconv.Itoa(ttl)))
+		w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%s, must-revalidate", strconv.Itoa(ttl)))
 		w.Header().Set("Expires", expires)
 		w.Header().Set("Last-Modified", lastModified)
 
diff --git a/ocis-pkg/middleware/static.go b/ocis-pkg/middleware/static.go
index 03d61ac0fe..d601a3eb7a 100644
--- a/ocis-pkg/middleware/static.go
+++ b/ocis-pkg/middleware/static.go
@@ -31,7 +31,7 @@ func Static(root string, fs http.FileSystem, ttl int) func(http.Handler) http.Ha
 			if strings.HasPrefix(r.URL.Path, path.Join(root, "api")) {
 				next.ServeHTTP(w, r)
 			} else {
-				w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%s", strconv.Itoa(ttl)))
+				w.Header().Set("Cache-Control", fmt.Sprintf("max-age=%s, must-revalidate", strconv.Itoa(ttl)))
 				w.Header().Set("Expires", expires)
 				w.Header().Set("Last-Modified", lastModified)
 				static.ServeHTTP(w, r)