diff --git a/lib/sidekiq/job_retry.rb b/lib/sidekiq/job_retry.rb
index f2156a32..1e8cf84f 100644
--- a/lib/sidekiq/job_retry.rb
+++ b/lib/sidekiq/job_retry.rb
@@ -215,7 +215,8 @@ module Sidekiq
 
     def retry_in(worker, count, exception)
       begin
-        worker.sidekiq_retry_in_block.call(count, exception).to_i
+        custom_retry_in = worker.sidekiq_retry_in_block.call(count, exception)
+        custom_retry_in.nil? ? nil : custom_retry_in.to_i
       rescue Exception => e
         handle_exception(e, { context: "Failure scheduling retry using the defined `sidekiq_retry_in` in #{worker.class.name}, falling back to default" })
         nil
diff --git a/test/test_retry.rb b/test/test_retry.rb
index 8e6c6d14..880abfcb 100644
--- a/test/test_retry.rb
+++ b/test/test_retry.rb
@@ -247,11 +247,16 @@ class TestRetry < Sidekiq::Test
         end
       end
 
+      class SpecialError < StandardError
+      end
+
       class CustomWorkerWithException
         include Sidekiq::Worker
 
         sidekiq_retry_in do |count, exception|
           case exception
+          when SpecialError
+            nil
           when ArgumentError
             count * 4
           else
@@ -280,6 +285,11 @@ class TestRetry < Sidekiq::Test
         assert_equal 4, handler.__send__(:delay_for, CustomWorkerWithException, 2, StandardError.new)
       end
 
+      it "retries with a default delay and exception in case of configured with nil" do
+        refute_equal 8, handler.__send__(:delay_for, CustomWorkerWithException, 2, SpecialError.new)
+        refute_equal 4, handler.__send__(:delay_for, CustomWorkerWithException, 2, SpecialError.new)
+      end
+
       it "retries with a custom delay without exception" do
         assert_equal 4, handler.__send__(:delay_for, CustomWorkerWithoutException, 2, StandardError.new)
       end