diff --git a/src/interfaces/libpq/fe-protocol3.c b/src/interfaces/libpq/fe-protocol3.c
index d3ca5d2..8345faf 100644
--- a/src/interfaces/libpq/fe-protocol3.c
+++ b/src/interfaces/libpq/fe-protocol3.c
@@ -880,6 +880,14 @@ pqGetErrorNotice3(PGconn *conn, bool isError)
 	char		id;
 
 	/*
+	 * If this is an error message, pre-emptively clear any incomplete query
+	 * result we may have.  We'd just throw it away below anyway, and
+	 * releasing it before collecting the error might avoid out-of-memory.
+	 */
+	if (isError)
+		pqClearAsyncResult(conn);
+
+	/*
 	 * Since the fields might be pretty long, we create a temporary
 	 * PQExpBuffer rather than using conn->workBuffer.  workBuffer is intended
 	 * for stuff that is expected to be short.  We shouldn't use
@@ -943,7 +951,7 @@ pqGetErrorNotice3(PGconn *conn, bool isError)
 	{
 		if (res)
 			res->errMsg = pqResultStrdup(res, workBuf.data);
-		pqClearAsyncResult(conn);
+		pqClearAsyncResult(conn);	/* redundant, but be safe */
 		conn->result = res;
 		if (PQExpBufferDataBroken(workBuf))
 			printfPQExpBuffer(&conn->errorMessage,