diff --git a/docs/api/cyclone/concurrent.md b/docs/api/cyclone/concurrent.md
index 8f2b3b81..382a298d 100644
--- a/docs/api/cyclone/concurrent.md
+++ b/docs/api/cyclone/concurrent.md
@@ -92,7 +92,7 @@ For example:
 Example programs:
 
 - Summing numbers using atomic operations: [`sum-atomic.scm`](../../../examples/threading/sum-atomic.scm)
-- For comparison, summing numbers using locks: [`sum-atomic.scm`](../../../examples/threading/sum-atomic.scm)
+- For comparison, summing numbers using locks: [`sum-mutex.scm`](../../../examples/threading/sum-mutex.scm)
 
 ### make-atom