--- a/src/SubProcess.cpp	Sat Jan 11 00:56:51 2020 +0100
+++ b/src/SubProcess.cpp	Sat Jan 11 00:58:35 2020 +0100
@@ -142,6 +142,8 @@
 			// Parent process
 			closeOrThrow(subInputReaderFD);
 			closeOrThrow(subOutputWriterFD);
+			fcntl(subInputWriterFD, F_SETFD, FD_CLOEXEC);
+			fcntl(subOutputReaderFD, F_SETFD, FD_CLOEXEC);
 			return new SubProcessImpl(subPid, subInputWriterFD, subOutputReaderFD);
 		}
 	}