diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 24e8404..2076d96 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -4637,6 +4637,16 @@ SubPostmasterMain(int argc, char *argv[])
 		strncmp(argv[1], "--forkbgworker=", 15) == 0)
 		PGSharedMemoryReAttach();
 
+	/*
+	 * Close any existing shared memory segment as those processes do not
+	 * need to have an access to it. This state is inherited from the
+	 * postmaster whether they need it or not.
+	 */
+	if (strcmp(argv[1], "--forkarch") == 0 ||
+		strcmp(argv[1], "--forkcol") == 0 ||
+		strcmp(argv[1], "--forklog") == 0)
+		PGSharedMemoryDetach();
+
 	/* autovacuum needs this set before calling InitProcess */
 	if (strcmp(argv[1], "--forkavlauncher") == 0)
 		AutovacuumLauncherIAm();