diff --git a/doc/api/child_processes.markdown b/doc/api/child_processes.markdown
index 418f82b648..4962ff4827 100644
--- a/doc/api/child_processes.markdown
+++ b/doc/api/child_processes.markdown
@@ -137,6 +137,10 @@ Example of checking for failed exec:
       }
     });
 
+Note that if spawn receives an empty options object, it will result in
+spawning the process with an empty environment rather than using
+`process.env`. This due to backwards compatibility issues with a deprecated
+API.
 
 See also: `child_process.exec()`