diff --git a/include/AbstractState.h b/include/AbstractState.h
index aedc6a79..ef021b4c 100644
--- a/include/AbstractState.h
+++ b/include/AbstractState.h
@@ -659,8 +659,15 @@ public:
     double fugacity(std::size_t i);
     /// Return the chemical potential of the i-th component of the mixture
     double chemical_potential(std::size_t i);
-    /// Return the fundamental derivative of gas dynamics
-    //double fundamental_derivative_of_gas_dynamics(void){return this->second_partial_deriv(iP, iDmolar, iSmolar, iDmolar, iSmolar)/pow(speed_sound(), 2)/2/pow(this->rhomolar(),3);};
+    /** \brief Return the fundamental derivative of gas dynamics \f$ \Gamma \f$
+     * 
+     * see also Colonna et al, FPE, 2010
+     *
+     * \f[ \Gamma = 1+\frac{\rho}{c}\left(\frac{partial c}{\partial \rho}\right)_{s} = 1+\frac{\rho}{2c^2}\left(\frac{partial^2 p}{\partial \rho^2}\right)_{s} = 1+\frac{v^3}{2c^2}\left(\frac{partial^2 p}{\partial v^2}\right)_{s}\f]
+     * 
+     * Note: densities are mass-based densities, not mole-based densities
+     */
+    double fundamental_derivative_of_gas_dynamics(void);
     /// Return the phase identification parameter (PIP) of G. Venkatarathnam and L.R. Oellrich, "Identification of the phase of a fluid using partial derivatives of pressure, volume, and temperature without reference to saturation properties: Applications in phase equilibria calculations"
     double PIP(){ return calc_PIP(); };
 
diff --git a/src/AbstractState.cpp b/src/AbstractState.cpp
index 3b1ba6e4..51f48462 100644
--- a/src/AbstractState.cpp
+++ b/src/AbstractState.cpp
@@ -408,6 +408,8 @@ double AbstractState::keyed_output(parameters key)
         return compressibility_factor();
     case iPIP:
         return PIP();
+    case ifundamental_derivative_of_gas_dynamics:
+        return fundamental_derivative_of_gas_dynamics();
     default:
         throw ValueError(format("This input [%d: \"%s\"] is not valid for keyed_output",key,get_parameter_information(key,"short").c_str()));
     }
@@ -548,6 +550,12 @@ double AbstractState::Cvirial(void){ return calc_Cvirial(); }
 double AbstractState::dBvirial_dT(void){ return calc_dBvirial_dT(); }
 double AbstractState::dCvirial_dT(void){ return calc_dCvirial_dT(); }
 double AbstractState::compressibility_factor(void){ return calc_compressibility_factor(); }
+    
+double AbstractState::fundamental_derivative_of_gas_dynamics()
+{
+    // See Colonna, FPE, 2010, Eq. 1
+    return 1 + this->second_partial_deriv(iP, iDmass, iSmolar, iDmass, iSmolar)*this->rhomass()/(2*powInt(speed_sound(), 2));
+};
 
 // Get the derivatives of the parameters in the partial derivative with respect to T and rho
 void get_dT_drho(AbstractState &AS, parameters index, CoolPropDbl &dT, CoolPropDbl &drho)
diff --git a/wrappers/Python/CoolProp/AbstractState.pxd b/wrappers/Python/CoolProp/AbstractState.pxd
index 6cfe2c6d..b0b46652 100644
--- a/wrappers/Python/CoolProp/AbstractState.pxd
+++ b/wrappers/Python/CoolProp/AbstractState.pxd
@@ -125,6 +125,7 @@ cdef class AbstractState:
     cpdef double Bvirial(self) except *
     cpdef double Cvirial(self) except *
     cpdef double PIP(self) except *
+    cpdef double fundamental_derivative_of_gas_dynamics(self) except *
     cpdef double isothermal_compressibility(self) except *
     cpdef double isobaric_expansion_coefficient(self) except *
     cpdef double fugacity(self, size_t) except *
diff --git a/wrappers/Python/CoolProp/AbstractState.pyx b/wrappers/Python/CoolProp/AbstractState.pyx
index a784c11f..163e42c2 100644
--- a/wrappers/Python/CoolProp/AbstractState.pyx
+++ b/wrappers/Python/CoolProp/AbstractState.pyx
@@ -302,6 +302,9 @@ cdef class AbstractState:
     cpdef double Cvirial(self) except *: 
         """ Get the C virial coefficient - wrapper of c++ function :cpapi:`CoolProp::AbstractState::Cvirial(void)` """
         return self.thisptr.Cvirial()
+    cpdef double fundamental_derivative_of_gas_dynamics(self) except *: 
+        """ Get the fundamental derivative of gas dynamics - wrapper of c++ function :cpapi:`CoolProp::AbstractState::fundamental_derivative_of_gas_dynamics(void)` """
+        return self.thisptr.fundamental_derivative_of_gas_dynamics()
     cpdef double PIP(self) except *: 
         """ Get the phase identification parameter - wrapper of c++ function :cpapi:`CoolProp::AbstractState::PIP(void)` """
         return self.thisptr.PIP()
diff --git a/wrappers/Python/CoolProp/cAbstractState.pxd b/wrappers/Python/CoolProp/cAbstractState.pxd
index 52e27fcb..dbc0d9d8 100644
--- a/wrappers/Python/CoolProp/cAbstractState.pxd
+++ b/wrappers/Python/CoolProp/cAbstractState.pxd
@@ -132,6 +132,7 @@ cdef extern from "AbstractState.h" namespace "CoolProp":
         double Bvirial() except +ValueError
         double Cvirial() except +ValueError
         double PIP() except +ValueError
+        double fundamental_derivative_of_gas_dynamics() except +ValueError
         double isothermal_compressibility() except +ValueError
         double isobaric_expansion_coefficient() except +ValueError
         double fugacity(size_t) except +ValueError