Disable false-positive C3P0 logs

My Java7 project uses c3p0 (0.9.5.1) for connection pooling and Log4j (1.2.17) for logging. It seems that log4j logs c3p0 INFO logs in ERROR level:

2017-02-09T21:30:19.545+01:00 app_r41 jsvclog[5135] err: JSVC [MLog-Init-Reporter] INFO com.mchange.v2.log.MLog - MLog clients using slf4j logging.
2017-02-09T21:30:19.959+01:00 app_r41 jsvclog[5135] err: JSVC [main] INFO com.mchange.v2.c3p0.C3P0Registry - Initializing c3p0-0.9.5.1 [built 16-June-2015 00:06:36 -0700; debug? true; trace: 10]
2017-02-09T21:30:21.294+01:00 app_r41 jsvclog[5135] err: JSVC [main] INFO com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource - [configuration of ComboPooledDataSource follows here...]

Now this is confusing and I want to disable it.

This is the relevant part of my log4j.properties configuration:

log4j.rootLogger=INFO, SYSLOG_APPENDER
log4j.logger.com.mchange=WARN, SYSLOG_APPENDER

What am I missing?

Solution

Setting this system property during service start-up fixes the problem:

System.setProperty( "com.mchange.v2.log.Log4jMLog.DEFAULT_CUTOFF_LEVEL", "WARNING" );