diff --git a/openems.cpp b/openems.cpp
index a3c15d2..e8291db 100644
--- a/openems.cpp
+++ b/openems.cpp
@@ -217,7 +217,7 @@ bool openEMS::parseCommandLineArgument( const char *argv )
 	}
 	else if (strncmp(argv,"--numThreads=",13)==0)
 	{
-		m_engine_numThreads = atoi(argv+13);
+		this->SetNumberOfThreads(atoi(argv+13));
 		cout << "openEMS - fixed number of threads: " << m_engine_numThreads << endl;
 		return true;
 	}
diff --git a/openems.h b/openems.h
index 1f6941a..6600e06 100644
--- a/openems.h
+++ b/openems.h
@@ -70,6 +70,8 @@ public:
 	void SetTimeStepFactor(double val) {m_TS_fac=val;}
 	void SetMaxTime(double val) {m_maxTime=val;}
 
+	void SetNumberOfThreads(unsigned int val) {m_engine_numThreads = val;}
+
 	void DebugMaterial() {DebugMat=true;}
 	void DebugOperator() {DebugOp=true;}
 	void DebugBox() {m_debugBox=true;}
diff --git a/python/openEMS/openEMS.pxd b/python/openEMS/openEMS.pxd
index 1b484ea..a307152 100644
--- a/python/openEMS/openEMS.pxd
+++ b/python/openEMS/openEMS.pxd
@@ -39,6 +39,8 @@ cdef extern from "openEMS/openems.h":
         void SetTimeStepFactor(double val)
         void SetMaxTime(double val)
 
+        void SetNumberOfThreads(int val)
+
         void Set_BC_Type(int idx, int _type)
         int Get_BC_Type(int idx)
         void Set_BC_PML(int idx, unsigned int size)
diff --git a/python/openEMS/openEMS.pyx b/python/openEMS/openEMS.pyx
index a449a34..bb41bff 100644
--- a/python/openEMS/openEMS.pyx
+++ b/python/openEMS/openEMS.pyx
@@ -410,7 +410,7 @@ cdef class openEMS:
                     continue
                 grid.AddLine(n, hint[n])
 
-    def Run(self, sim_path, cleanup=False, setup_only=False, debug_pec=False, verbose=None):
+    def Run(self, sim_path, cleanup=False, setup_only=False, debug_pec=False, verbose=None, **kw):
         """ Run(sim_path, cleanup=False, setup_only=False, verbose=None)
 
         Run the openEMS FDTD simulation.
@@ -419,6 +419,9 @@ cdef class openEMS:
         :param cleanup: bool -- remove exisiting sim_path to cleanup old results
         :param setup_only: bool -- only perform FDTD setup, do not run simulation
         :param verbose: int -- set the openEMS verbosity level 0..3
+
+        Additional keyword parameter:
+        :param numThreads: int -- set the number of threads (default 0 --> max)
         """
         if cleanup and os.path.exists(sim_path):
             shutil.rmtree(sim_path)
@@ -431,6 +434,8 @@ cdef class openEMS:
             self.thisptr.SetVerboseLevel(verbose)
         if debug_pec:
             self.thisptr.DebugPEC()
+        if 'numThreads' in kw:
+            self.thisptr.SetNumberOfThreads(int(kw['numThreads']))
         assert os.getcwd() == sim_path
         _openEMS.WelcomeScreen()
         cdef int EC