diff --git a/docs/api/srfi/18.md b/docs/api/srfi/18.md
index 0cdb07df..bce4a03a 100644
--- a/docs/api/srfi/18.md
+++ b/docs/api/srfi/18.md
@@ -79,11 +79,11 @@ Makes thread runnable. The thread must be a new thread. thread-start! returns th
 
     (thread-sleep! timeout)
 
-Block the current thread for `timeout` milliseconds.
+Block the current thread for `timeout` seconds. Specify fractional seconds for high-resolution timing.
 
 # thread-yield!
 
-    (thread-yield!) (thread-sleep! 1))
+    (thread-yield!)
 
 The current thread exits the running state as if its quantum had expired.