diff --git a/src/fiber/execution_context.cr b/src/fiber/execution_context.cr
index 17ddc018270b..25ba381e74f1 100644
--- a/src/fiber/execution_context.cr
+++ b/src/fiber/execution_context.cr
@@ -25,7 +25,13 @@ module Fiber::ExecutionContext
     @@monitor = Monitor.new
   end
 
-  # Returns the default number of workers to start in the execution context.
+  # Returns the number of threads to start in the default multi threaded
+  # execution context. Respects the `CRYSTAL_WORKERS` environment variable
+  # and otherwise returns the potential parallelism of the CPU (number of
+  # hardware threads).
+  #
+  # Currently unused because the default context is single threaded for
+  # now (this might change later with compilation flags).
   def self.default_workers_count : Int32
     ENV["CRYSTAL_WORKERS"]?.try(&.to_i?) || Math.min(System.cpu_count.to_i, 32)
   end