diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c
index 10cc05d5e4b..42da83b9706 100644
--- a/src/backend/libpq/be-fsstubs.c
+++ b/src/backend/libpq/be-fsstubs.c
@@ -489,7 +489,7 @@ be_lo_export(PG_FUNCTION_ARGS)
 	text	   *filename = PG_GETARG_TEXT_PP(1);
 	int			fd;
 	int			nbytes;
-	char		buf[BUFSIZE];
+	char	   *buf;
 	char		fnamebuf[MAXPGPATH];
 	LargeObjectDesc *lobj;
 	mode_t		oumask;
@@ -525,6 +525,13 @@ be_lo_export(PG_FUNCTION_ARGS)
 				 errmsg("could not create server file \"%s\": %m",
 						fnamebuf)));
 
+	/*
+	 * The buffer is allocated rather than declared on the stack. A frame
+	 * larger than 4kB that contains a PG_TRY() can be miscompiled by GCC on
+	 * SPARC.
+	 */
+	buf = palloc(BUFSIZE);
+
 	/*
 	 * read in from the inversion file and write to the filesystem
 	 */
@@ -540,6 +547,8 @@ be_lo_export(PG_FUNCTION_ARGS)
 							fnamebuf)));
 	}
 
+	pfree(buf);
+
 	if (CloseTransientFile(fd) != 0)
 		ereport(ERROR,
 				(errcode_for_file_access(),