diff --git a/MAC/Services/src/ObservationControl2.py b/MAC/Services/src/ObservationControl2.py
index 3e669c3c5f30413003df7d9047c3849ab3507900..2c4854c7db5b8afb2e0bce490762772aeed72863 100644
--- a/MAC/Services/src/ObservationControl2.py
+++ b/MAC/Services/src/ObservationControl2.py
@@ -85,7 +85,7 @@ def main():
                           description='runs the observationcontrol service')
     parser.add_option('-b', '--broker', dest='broker', type='string', default=DEFAULT_BROKER,
                       help='Address of the qpid broker, default: %default')
-    parser.add_option("-e", "--exchange", dest="echange", type="string",
+    parser.add_option("-e", "--exchange", dest="exchange", type="string",
                       default=DEFAULT_BUSNAME,
                       help="Name of the exchange on the qpid broker, default: %default")
     parser.add_option('-V', '--verbose', dest='verbose', action='store_true',