diff --git a/interfaces/cython/cantera/_cantera.pxd b/interfaces/cython/cantera/_cantera.pxd
index 8ce73ece71..c53887c63d 100644
--- a/interfaces/cython/cantera/_cantera.pxd
+++ b/interfaces/cython/cantera/_cantera.pxd
@@ -474,6 +474,8 @@ cdef extern from "cantera/zeroD/Reactor.h":
     cdef cppclass CxxReactor "Cantera::Reactor" (CxxReactorBase):
         CxxReactor()
         void setKineticsMgr(CxxKinetics&)
+        void setChemistry(cbool)
+        cbool chemistryEnabled()
         void setEnergy(int)
         cbool energyEnabled()
         size_t componentIndex(string&)
diff --git a/interfaces/cython/cantera/reactor.pyx b/interfaces/cython/cantera/reactor.pyx
index 5351dd2b9e..ed76b10892 100644
--- a/interfaces/cython/cantera/reactor.pyx
+++ b/interfaces/cython/cantera/reactor.pyx
@@ -201,6 +201,18 @@ cdef class Reactor(ReactorBase):
             self.rbase.restoreState()
             return self._kinetics
 
+    property chemistry_enabled:
+        """
+        *True* when the reactor composition is allowed to change due to
+        chemical reactions in this reactor. When this is *False*, the
+        reactor composition is held constant.
+        """
+        def __get__(self):
+            return self.reactor.chemistryEnabled()
+
+        def __set__(self, pybool value):
+            self.reactor.setChemistry(value)
+
     property energy_enabled:
         """
         *True* when the energy equation is being solved for this reactor.