diff --git a/tools/doc/Cantera.cfg.in b/tools/doc/Cantera.cfg.in
index 31d7c80bf..6c8322c87 100755
--- a/tools/doc/Cantera.cfg.in
+++ b/tools/doc/Cantera.cfg.in
@@ -146,6 +146,7 @@ FILE_PATTERNS          = Kinetics.h Kinetics.cpp \
                          PDSS_IdealGas.h  PDSS_IdealGas.cpp \
                          PDSS_Water.h PDSS_Water.cpp \
                          PDSS_HKFT.h PDSS_HKFT.cpp \
+                         PDSS_SSVol.h PDSS_SSVol.cpp \
                          IdealSolnGasVPSS.h IdealSolnGasVPSS.cpp \
                          ConstDensityThermo.h ConstDensityThermo.cpp \
                          WaterPropsIAPWSphi.h  WaterPropsIAPWSphi.cpp \