diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 33bb0229aa..221e4cb34f 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -1265,7 +1265,7 @@ XLogInsertRecord(XLogRecData *rdata,
 
 		if (!debug_reader)
 		{
-			appendStringInfoString(&buf, "error decoding record: out of memory");
+			appendStringInfoString(&buf, "error decoding record: out of memory while allocating a WAL reading processor");
 		}
 		else if (!DecodeXLogRecord(debug_reader, (XLogRecord *) recordBuf.data,
 								   &errormsg))
diff --git a/src/backend/replication/logical/logical.c b/src/backend/replication/logical/logical.c
index b7d9521576..10cbdea124 100644
--- a/src/backend/replication/logical/logical.c
+++ b/src/backend/replication/logical/logical.c
@@ -202,7 +202,8 @@ StartupDecodingContext(List *output_plugin_options,
 	if (!ctx->reader)
 		ereport(ERROR,
 				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
+				 errmsg("out of memory"),
+				 errdetail("Failed while allocating a WAL reading processor.")));
 
 	ctx->reorder = ReorderBufferAllocate();
 	ctx->snapshot_builder =
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 7950afb173..84915ed95b 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -681,7 +681,8 @@ StartReplication(StartReplicationCmd *cmd)
 	if (!xlogreader)
 		ereport(ERROR,
 				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
+				 errmsg("out of memory"),
+				 errdetail("Failed while allocating a WAL reading processor.")));
 
 	/*
 	 * We assume here that we're logging enough information in the WAL for
diff --git a/src/bin/pg_rewind/parsexlog.c b/src/bin/pg_rewind/parsexlog.c
index 59ebac7d6a..436df54120 100644
--- a/src/bin/pg_rewind/parsexlog.c
+++ b/src/bin/pg_rewind/parsexlog.c
@@ -74,7 +74,7 @@ extractPageMap(const char *datadir, XLogRecPtr startpoint, int tliIndex,
 									XL_ROUTINE(.page_read = &SimpleXLogPageRead),
 									&private);
 	if (xlogreader == NULL)
-		pg_fatal("out of memory");
+		pg_fatal("out of memory while allocating a WAL reading processor");
 
 	XLogBeginRead(xlogreader, startpoint);
 	do
@@ -132,7 +132,7 @@ readOneRecord(const char *datadir, XLogRecPtr ptr, int tliIndex,
 									XL_ROUTINE(.page_read = &SimpleXLogPageRead),
 									&private);
 	if (xlogreader == NULL)
-		pg_fatal("out of memory");
+		pg_fatal("out of memory while allocating a WAL reading processor");
 
 	XLogBeginRead(xlogreader, ptr);
 	record = XLogReadRecord(xlogreader, &errormsg);
@@ -192,7 +192,7 @@ findLastCheckpoint(const char *datadir, XLogRecPtr forkptr, int tliIndex,
 									XL_ROUTINE(.page_read = &SimpleXLogPageRead),
 									&private);
 	if (xlogreader == NULL)
-		pg_fatal("out of memory");
+		pg_fatal("out of memory while allocating a WAL reading processor");
 
 	searchptr = forkptr;
 	for (;;)
diff --git a/src/bin/pg_waldump/pg_waldump.c b/src/bin/pg_waldump/pg_waldump.c
index 1e3894b9c4..4690e0f515 100644
--- a/src/bin/pg_waldump/pg_waldump.c
+++ b/src/bin/pg_waldump/pg_waldump.c
@@ -1061,7 +1061,7 @@ main(int argc, char **argv)
 									  .segment_close = WALDumpCloseSegment),
 						   &private);
 	if (!xlogreader_state)
-		fatal_error("out of memory");
+		fatal_error("out of memory while allocating a WAL reading processor");
 
 	/* first find a valid recptr to start from */
 	first_record = XLogFindNextRecord(xlogreader_state, private.startptr);