diff --git a/api/semaphore.go b/api/semaphore.go
index 88f4b59cce..c1c467a957 100644
--- a/api/semaphore.go
+++ b/api/semaphore.go
@@ -29,7 +29,7 @@ const (
 
 	// DefaultSemaphoreKey is the key used within the prefix to
 	// use for coordination between all the contenders.
-	DefaultSemaphoreKey = "_lock"
+	DefaultSemaphoreKey = ".lock"
 )
 
 var (