diff --git a/doc/nghttpx.1 b/doc/nghttpx.1
index a6650af9..3fd6522c 100644
--- a/doc/nghttpx.1
+++ b/doc/nghttpx.1
@@ -1706,7 +1706,7 @@ parameter.  All requests which come from this frontend address, will
 be treated as API request.
 .sp
 The following section describes available API endpoints.
-.SS PUT /api/v1beta/backend/replace
+.SS PUT /api/v1beta1/backend/replace
 .sp
 This API replaces the current set of backend servers with the
 requested ones.  The request must carry request body with method PUT
diff --git a/doc/nghttpx.1.rst b/doc/nghttpx.1.rst
index d8306e9d..763e3d75 100644
--- a/doc/nghttpx.1.rst
+++ b/doc/nghttpx.1.rst
@@ -1550,8 +1550,8 @@ be treated as API request.
 
 The following section describes available API endpoints.
 
-PUT /api/v1beta/backend/replace
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+PUT /api/v1beta1/backend/replace
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 This API replaces the current set of backend servers with the
 requested ones.  The request must carry request body with method PUT