diff --git a/interfaces/matlab/toolbox/@ThermoPhase/set.m b/interfaces/matlab/toolbox/@ThermoPhase/set.m
index 87dda95805..7e348643da 100644
--- a/interfaces/matlab/toolbox/@ThermoPhase/set.m
+++ b/interfaces/matlab/toolbox/@ThermoPhase/set.m
@@ -170,6 +170,8 @@ function set(tp, varargin)
     elseif nt == 1 && np == 1
         setTemperature(tp, tval);
         setPressure(tp, pval);
+    elseif np == 1 && nv == 1
+        setState_RP(tp, [1.0/vval, pval])
     elseif nt == 1 && nq == 1
         setState_Tsat(tp, [tval,qval]);
     elseif np == 1 && nq == 1
diff --git a/interfaces/matlab/toolbox/@ThermoPhase/setState_RP.m b/interfaces/matlab/toolbox/@ThermoPhase/setState_RP.m
new file mode 100644
index 0000000000..4f5fe1aba6
--- /dev/null
+++ b/interfaces/matlab/toolbox/@ThermoPhase/setState_RP.m
@@ -0,0 +1,16 @@
+function setState_RP(tp, rp)
+% SETSTATE_RP  Set the density and pressure.
+% setState_RP(tp, [density,p])
+% The density is set first, then the pressure is set by
+% changing the temperature holding the density and
+% chemical composition fixed.
+%
+% :param tp:
+%     Instance of class :mat:func:`ThermoPhase` (or another
+%     class derived from ThermoPhase)
+% :param rp:
+%     Vector of length 2 containing the desired values for the density (kg/m^3)
+%     and pressure (Pa)
+%
+
+thermo_set(tp.tp_id, 26, rp);
diff --git a/src/clib/ct.cpp b/src/clib/ct.cpp
index 3435bd00a1..452c04dc9c 100644
--- a/src/clib/ct.cpp
+++ b/src/clib/ct.cpp
@@ -535,6 +535,16 @@ extern "C" {
         }
     }
 
+    int th_set_RP(int n, double* vals)
+    {
+        try{
+            ThermoCabinet::item(n).setState_RP(vals[0], vals[1]);
+            return 0;
+        } catch (...) {
+            return handleAllExceptions(-1, ERR);
+        }
+    }
+
     int th_set_HP(int n, double* vals)
     {
         try {
diff --git a/src/clib/ct.h b/src/clib/ct.h
index 4da53876cb..ead3914956 100644
--- a/src/clib/ct.h
+++ b/src/clib/ct.h
@@ -73,6 +73,7 @@ extern "C" {
     CANTERA_CAPI int th_getEntropies_R(int n, size_t lenm, double* s_r);
     CANTERA_CAPI int th_getCp_R(int n, size_t lenm, double* cp_r);
     CANTERA_CAPI int th_setElectricPotential(int n, double v);
+    CANTERA_CAPI int th_set_RP(int n, double* vals);
     CANTERA_CAPI int th_set_HP(int n, double* vals);
     CANTERA_CAPI int th_set_UV(int n, double* vals);
     CANTERA_CAPI int th_set_SV(int n, double* vals);
diff --git a/src/matlab/thermomethods.cpp b/src/matlab/thermomethods.cpp
index a0e8dc89ea..e82604d325 100644
--- a/src/matlab/thermomethods.cpp
+++ b/src/matlab/thermomethods.cpp
@@ -60,6 +60,9 @@ static void thermoset(int nlhs, mxArray* plhs[],
             case 25:
                 ierr = th_setState_Tsat(th,ptr[0],ptr[1]);
                 break;
+            case 26:
+                ierr = th_set_RP(th,ptr);
+                break;
             default:
                 mexErrMsgTxt("unknown pair attribute.");
             }