diff --git a/src/bin/pg_dump/pg_backup_tar.c b/src/bin/pg_dump/pg_backup_tar.c
index 0e547e83be..a6acd85f60 100644
--- a/src/bin/pg_dump/pg_backup_tar.c
+++ b/src/bin/pg_dump/pg_backup_tar.c
@@ -1085,11 +1085,13 @@ _tarAddFile(ArchiveHandle *AH, TAR_MEMBER *th)
 	/*
 	 * Find file len & go back to start.
 	 */
-	fseeko(tmp, 0, SEEK_END);
+	if (fseeko(tmp, 0, SEEK_END) != 0)
+		fatal("error during file seek: %m");
 	th->fileLen = ftello(tmp);
 	if (th->fileLen < 0)
 		fatal("could not determine seek position in archive file: %m");
-	fseeko(tmp, 0, SEEK_SET);
+	if (fseeko(tmp, 0, SEEK_SET) != 0)
+		fatal("error during file seek: %m");
 
 	_tarWriteHeader(th);