diff --git a/doc/musrfit_dox.cfg b/doc/musrfit_dox.cfg
index 57cf3852..91f40a20 100644
--- a/doc/musrfit_dox.cfg
+++ b/doc/musrfit_dox.cfg
@@ -761,6 +761,7 @@ INPUT                  = musrfit.dox \
                          ../src/include/PRunSingleHistoRRF.h \
                          ../src/include/PStartupHandler.h \
                          ../src/include/PStartupHandlerLinkDef.h \
+                         ../src/include/PStringUtils.h \
                          ../src/include/PTheory.h \
                          ../src/include/PUserFcnBase.h \
                          ../src/include/PUserFcnBaseLinkDef.h \
@@ -787,6 +788,7 @@ INPUT                  = musrfit.dox \
                          ../src/classes/PRunSingleHisto.cpp \
                          ../src/classes/PRunSingleHistoRRF.cpp \
                          ../src/classes/PStartupHandler.cpp \
+                         ../src/classes/PStringUtils.cpp \
                          ../src/classes/PTheory.cpp \
                          ../src/classes/PUserFcnBase.cpp \
                          ../src/classes/PUserFcn.cpp \