diff --git a/python/CMakeLists.txt b/python/CMakeLists.txt
index 044f65e..824ad54 100644
--- a/python/CMakeLists.txt
+++ b/python/CMakeLists.txt
@@ -82,7 +82,7 @@ ENDIF(PYQT4_VERSION_NUM LESS 264196)
 # core module
 FILE(GLOB_RECURSE sip_files_core core/*.sip)
 SET(SIP_EXTRA_FILES_DEPEND ${sip_files_core})
-SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -o -a ${CMAKE_BINARY_DIR}/python/qgis.core.api)
+SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -a ${CMAKE_BINARY_DIR}/python/qgis.core.api)
 ADD_SIP_PYTHON_MODULE(qgis.core core/core.sip qgis_core)
 
 # additional gui includes
@@ -97,7 +97,7 @@ INCLUDE_DIRECTORIES(
 # gui module
 FILE(GLOB_RECURSE sip_files_gui gui/*.sip)
 SET(SIP_EXTRA_FILES_DEPEND ${sip_files_core} ${sip_files_gui})
-SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -o -a ${CMAKE_BINARY_DIR}/python/qgis.gui.api)
+SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -a ${CMAKE_BINARY_DIR}/python/qgis.gui.api)
 
 IF(UNIX AND NOT SIP_VERSION_NUM LESS 265984)
   SET(SIP_EXTRA_OPTIONS -P ${SIP_EXTRA_OPTIONS})
@@ -126,13 +126,13 @@ FILE(GLOB sip_files_analysis
   analysis/interpolation/*.sip
 )
 SET(SIP_EXTRA_FILES_DEPEND ${sip_files_core} ${sip_files_analysis})
-SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -o -a ${CMAKE_BINARY_DIR}/python/qgis.analysis.api)
+SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -a ${CMAKE_BINARY_DIR}/python/qgis.analysis.api)
 ADD_SIP_PYTHON_MODULE(qgis.analysis analysis/analysis.sip qgis_core qgis_analysis)
 
 # network-analysis module
 FILE(GLOB_RECURSE sip_files_network_analysis analysis/network/*.sip)
 SET(SIP_EXTRA_FILES_DEPEND ${sip_files_core} ${sip_files_network_analysis})
-SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -o -a ${CMAKE_BINARY_DIR}/python/qgis.networkanalysis.api)
+SET(SIP_EXTRA_OPTIONS ${PYQT4_SIP_FLAGS} -a ${CMAKE_BINARY_DIR}/python/qgis.networkanalysis.api)
 ADD_SIP_PYTHON_MODULE(qgis.networkanalysis analysis/network/networkanalysis.sip qgis_core qgis_networkanalysis)
 
 SET(QGIS_PYTHON_DIR ${PYTHON_SITE_PACKAGES_DIR}/qgis)