diff --git a/BuildBotLib/basemodule.py b/BuildBotLib/basemodule.py
index 0ad0a72..fe39a9c 100644
--- a/BuildBotLib/basemodule.py
+++ b/BuildBotLib/basemodule.py
@@ -97,7 +97,7 @@ class BaseModule:
 
         return 'make'
 
-    def makeTarget(self, target, cxxFlags=None):
+    def makeTarget(self, target, cxxFlags=[]):
         command = [self.make()]
         return command + [target]
 
diff --git a/BuildBotLib/cmake.py b/BuildBotLib/cmake.py
index d2c0c5c..1871584 100644
--- a/BuildBotLib/cmake.py
+++ b/BuildBotLib/cmake.py
@@ -15,7 +15,7 @@ class CMake(Make):
     def makePrefix(self):
         return "C"
 
-    def makeTarget(self, target, cxxFlags=None):
+    def makeTarget(self, target, cxxFlags=[]):
         command = 'cmake --build cmake_build --config Release'
 
         if len(target):
@@ -25,9 +25,7 @@ class CMake(Make):
             if cpus:
                 command += ' --parallel ' + str(cpus)
 
-        cxx = []
-        if cxxFlags is not None:
-            cxx += cxxFlags
+        cxx = cxxFlags
 
         if self.isiOS(''):
             cxx += ['-allowProvisioningUpdates']
diff --git a/master.cfg b/master.cfg
index 9b6bea4..f193676 100644
--- a/master.cfg
+++ b/master.cfg
@@ -32,11 +32,12 @@ cmakeAndroid = CMake(BaseModule.P_Android)
 wasm = CMake(BaseModule.P_Wasm)
 docs = Docs(BaseModule.P_Linux)
 
+iosBuilder = CMake(BaseModule.P_iOS)
+
 repoGen = QIFRepogen()
 
 release = Releaser()
 
-iosBuilder = CMake(BaseModule.P_iOS)
 
 bot.addBuilder("LinuxBuilder", qmakeLinux)
 bot.addBuilder("WindowsBuilder", qmakeWindows)