diff --git a/rootfs/etc/nginx/lua/configuration.lua b/rootfs/etc/nginx/lua/configuration.lua
index 2a0762383..4ab894e2c 100644
--- a/rootfs/etc/nginx/lua/configuration.lua
+++ b/rootfs/etc/nginx/lua/configuration.lua
@@ -102,7 +102,7 @@ local function handle_servers()
 
   for uid, cert in pairs(configuration.certificates) do
     local old_cert = certificate_data:get(uid)
-    if old_cert ~= cert then
+    if old_cert ~= nil and old_cert ~= cert then
         ocsp_response_cache:delete(uid)
     end
 
diff --git a/rootfs/etc/nginx/lua/test/configuration_test.lua b/rootfs/etc/nginx/lua/test/configuration_test.lua
index cb301ba61..ce00980b3 100644
--- a/rootfs/etc/nginx/lua/test/configuration_test.lua
+++ b/rootfs/etc/nginx/lua/test/configuration_test.lua
@@ -197,7 +197,7 @@ describe("Configuration", function()
 
       local s = spy.on(ngx.shared.ocsp_response_cache, "delete")
       assert.has_no.errors(configuration.handle_servers)
-      assert.spy(s).was_not_called_with(UUID)
+      assert.spy(s).was_not_called()
     end)
 
     it("should not delete ocsp_response_cache if certificate is empty", function()
@@ -212,7 +212,7 @@ describe("Configuration", function()
 
       local s = spy.on(ngx.shared.ocsp_response_cache, "delete")
       assert.has_no.errors(configuration.handle_servers)
-      assert.spy(s).was_not_called_with(UUID)
+      assert.spy(s).was_not_called()
     end)
 
     it("should delete ocsp_response_cache if certificate changed", function()