diff --git a/Control/AthenaMPTools/src/SharedWriterTool.cxx b/Control/AthenaMPTools/src/SharedWriterTool.cxx
index 1c3c22c2d2f93e4ea1996c4a7cebc0ce6ffe0927..93fedbd8cd3a916ddf6fcd948eee86fc319a4922 100644
--- a/Control/AthenaMPTools/src/SharedWriterTool.cxx
+++ b/Control/AthenaMPTools/src/SharedWriterTool.cxx
@@ -154,7 +154,7 @@ std::unique_ptr<AthenaInterprocess::ScheduledWork> SharedWriterTool::bootstrap_f
   ATH_MSG_INFO("File descriptors re-opened in the AthenaMP Shared Writer PID=" << getpid());
 
   // FIXME: IEventShare ...
-  if(!m_evtShare->makeServer(m_nprocs).isSuccess()) {
+  if(!m_evtShare->makeServer(-m_nprocs).isSuccess()) {
     ATH_MSG_ERROR("Failed to make the event selector a share server");
     return outwork;
   }