diff --git a/src/main/main.pro b/src/main/main.pro
index 20b73e14b..472fff491 100644
--- a/src/main/main.pro
+++ b/src/main/main.pro
@@ -32,5 +32,6 @@ os2:RC_FILE = appicon_os2.rc
 win32:RC_FILE = appicon.rc
 
 include(../install.pri)
+include(../lib/3rdparty/qtsingleapplication/qtsingleapplication.pri)
 
 unix:contains(DEFINES, "NO_SYSTEM_DATAPATH"): QMAKE_LFLAGS+=$${QMAKE_LFLAGS_RPATH}\\$\$ORIGIN