diff --git a/src/include/postmaster/postmaster.h b/src/include/postmaster/postmaster.h
index 4cc59a662ee..63c12917cfe 100644
--- a/src/include/postmaster/postmaster.h
+++ b/src/include/postmaster/postmaster.h
@@ -63,8 +63,6 @@ extern int	MaxLivePostmasterChildren(void);
 
 extern bool PostmasterMarkPIDForWorkerNotify(int);
 
-extern void processCancelRequest(int backendPID, int32 cancelAuthCode);
-
 #ifdef WIN32
 extern void pgwin32_register_deadchild_callback(HANDLE procHandle, DWORD procId);
 #endif