diff --git a/gems/concurrent-ruby/1.1/utility/processor_counter.rbs b/gems/concurrent-ruby/1.1/utility/processor_counter.rbs
new file mode 100644
index 00000000..50e6a5a1
--- /dev/null
+++ b/gems/concurrent-ruby/1.1/utility/processor_counter.rbs
@@ -0,0 +1,5 @@
+module Concurrent
+  def self.physical_processor_count: () -> Integer
+
+  def self.processor_count: () -> Integer
+end