diff --git a/src/Makefile.am b/src/Makefile.am
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,230 +1,234 @@
 SUBDIRS = defaults snippets Matchbox Merging
 
 defaultsdir = ${pkgdatadir}/defaults
 
 bin_PROGRAMS = Herwig
 
 Herwig_SOURCES = \
 HerwigMain.cc HerwigCLI.cc HerwigCLI.h \
 herwigopts.c herwigopts.h
 
 BUILT_SOURCES = herwigopts.c herwigopts.h
 
 Herwig_LDFLAGS = $(AM_LDFLAGS) -export-dynamic $(THEPEGLDFLAGS)
 Herwig_LDADD = $(THEPEGLIB) -ldl \
 $(top_builddir)/API/libHerwigAPI.la
 
 bin_SCRIPTS = herwig-config
 
 HELPERFILES = \
 CMSSM40.1.1.slha \
 NMSSM.spc \
 ADD.model \
 Leptoquark.model \
 LH.model \
 LHTP.model \
 MSSM.model \
 MUED.model \
 NMSSM.model \
 RPV-Bi.model \
 RPV-Tri.model \
 RS.model \
 Sextet.model \
 TTBA.model \
 Zprime.model \
 RPV-BI.slha \
 RPV-TRI.slha \
 RPV-UDD.slha
 
 INPUTFILES = \
 DIS.in \
 DIS-Matchbox.in \
 GammaGamma.in \
 ILC.in \
 ILC-MSSM.in \
 ILC-MUED.in \
 ILC-RS.in \
 LEP.in \
 LEP-Matchbox.in \
 LHC-ADD.in \
 LHC-CEX.in \
 LHC-GammaGamma.in \
 LHC-ResolvedGammaGamma.in \
 LHC.in \
 LHC-Matchbox.in \
 LHC-LQ.in \
 LHC-MSSM.in \
 LHC-MUED.in \
 LHC-NMSSM.in \
 LHC-Powheg.in \
 LHC-RPV.in \
 LHC-RS.in \
 LHC-Sextet.in \
 LHC-TRP.in \
 LHC-TTBA.in \
 LHC-MB.in \
 LHC-ZP.in \
 TVT.in \
 TVT-Powheg.in \
 TVT-TTBA.in \
 LHC-LH.in \
 LHC-LHTP.in \
 LHE.in \
 LHE-POWHEG.in \
 LHE-MCatNLO.in \
 LHE-FxFx.in \
 LHE-MGMerging.in
 
 dist_pkgdata_DATA = $(INPUTFILES) $(HELPERFILES)
 pkgdata_DATA = Makefile-UserModules
 
 CLEANFILES = HerwigDefaults.rpo \
   *.run *.log *.out *.tex \
   multi.test *.output probs.test chisq.value \
   LHC-RS-BR.spc LHC-MSSM-BR.spc LHC-RPV-BR.spc
 
 clean-local:
 	-rm -rf Herwig
 
 ## checking targets ##
 
 HerwigDefaults.rpo: Herwig $(srcdir)/defaults/*.in defaults/PDF.in defaults/Analysis.in $(top_builddir)/lib/*.so
 	./Herwig init -L$(top_builddir)/lib defaults/HerwigDefaults.in -D
 
 check_BSM_Full=
 check_BSM=
 
 if WANT_BSM
 
 check_BSM += check-LHC-RPV check-LHC-RS
 
 check_BSM_Full += \
 check-LHC-RPV check-LHC-MSSM check-ILC-MSSM \
 check-LHC-NMSSM \
 check-LHC-MUED check-ILC-MUED \
 check-LHC-RS check-ILC-RS check-LHC-ADD \
 check-LHC-LH check-LHC-LHTP \
 check-LHC-TRP \
 check-LHC-TTBA check-TVT-TTBA \
 check-LHC-ZP \
 check-LHC-LQ \
 check-LHC-Sextet
 
 endif
 check_BSM_Full_valgrind = $(subst check,check-valgrind,$(check_BSM_Full))
 check_BSM_valgrind = $(subst check,check-valgrind,$(check_BSM))
 
 check-local: check-LEP check-LHC $(check_BSM) check-DIS check-ILC check-GammaGamma check-LHC-Powheg
 
 check-valgrind-local: check-valgrind-LEP check-valgrind-LHC $(check_BSM_valgrind) check-valgrind-DIS check-valgrind-ILC check-valgrind-GammaGamma check-valgrind-LHC-Powheg
 
 check-Powheg: check-LHC-Powheg check-TVT-Powheg
 
 check-valgrind-Powheg: check-valgrind-LHC-Powheg check-valgrind-TVT-Powheg
 
 check-BSM: $(check_BSM_Full)
 
 check-valgrind-BSM: $(check_BSM_Full_valgrind)
 
 check_Matchbox= \
 check-LEP-Matchbox check-DIS-Matchbox check-LHC-Matchbox
 check_Matchbox_valgrind = $(subst check,check-valgrind,$(check_Matchbox))
 
 check-Matchbox: $(check_Matchbox)
 
 check-valgrind-Matchbox: $(check_Matchbox_valgrind)
 
 check-extra: check-LHC-CEX check-LHC-GammaGamma check-LHC-ResolvedGammaGamma check-LHC-MB check-TVT
 
 check-valgrind-extra: check-valgrind-LHC-CEX check-valgrind-LHC-GammaGamma check-valgrind-LHC-MB check-valgrind-TVT
 
 check-all: check-local check-Powheg check-BSM check-Matchbox check-extra
 
 check-valgrind-all: check-valgrind-local check-valgrind-Powheg check-valgrind-BSM check-valgrind-Matchbox check-valgrind-extra
 
 link-helper-files:
 	@for i in $(HELPERFILES); do \
 	if test -f $(srcdir)/$$i -a ! -e $$i; then \
 	$(LN_S) -f $(srcdir)/$$i; fi; done
 
 ## valgrind targets ##
 
 VALGRIND=valgrind --leak-check=full --num-callers=25 --freelist-vol=100000000 --leak-resolution=med --trace-children=yes
 
 check-valgrind-%: $(srcdir)/%.in HerwigDefaults.rpo link-helper-files
 	$(VALGRIND) ./Herwig read -d1 -D $< &> valgrind-$(notdir $(subst .in,,$<))-read.log
 	$(VALGRIND) ./Herwig run $(notdir $(subst .in,.run,$<)) -N 500 -d1 -D &> valgrind-$(notdir $(subst .in,,$<))-run.log
 
 valgrind: valgrind-init valgrind-read valgrind-run
 
 valgrind-init:
 	$(VALGRIND) ./Herwig init -d1 -D -L$(top_builddir)/lib defaults/HerwigDefaults.in \
 &> /tmp/valgrind-init.log
 valgrind-read:
 	$(VALGRIND) ./Herwig read -d1 -D LHC.in &> /tmp/valgrind-read.log
 valgrind-run:
 	$(VALGRIND) ./Herwig run -d1 -D -N5 LHC.run &> /tmp/valgrind-run.log
 
 CHECKCOMMAND = ./Herwig run  $(notdir $(subst .in,.run,$<)) -N500 -d1 -D
 
 check-%: $(srcdir)/%.in HerwigDefaults.rpo link-helper-files
 	./Herwig read -i . $< -D
 	@echo $(CHECKCOMMAND)
 	@$(CHECKCOMMAND) && echo "# $@ OK #" \
 			 || (echo "###### $@ BAD ######"; false)
 SETUPTHEPEG=$(THEPEGPATH)/bin/setupThePEG
 THEPEGREPO=$(THEPEGLIBPATH)/ThePEGDefaults.rpo
 
 install-data-hook:
 	@echo Creating repository
+
+	@if [ "$(PYTHON_PLATFORM)" = "darwin" ]; then\
+				install_name_tool -add_rpath $(DESTDIR)$(libdir) $(DESTDIR)$(pkglibdir)/HwEvtGenInterface.so;\
+	fi
+
 	@./Herwig init -L$(DESTDIR)$(pkglibdir) -i$(DESTDIR)$(pkgdatadir) -i$(DESTDIR)$(pkgdatadir)/snippets $(DESTDIR)$(defaultsdir)/HerwigDefaults.in --repo=$(DESTDIR)$(pkgdatadir)/HerwigDefaults.rpo
 	@if test -n "$(DESTDIR)"; \
         then sed -i.bak -e "s@$(DESTDIR)@@g" $(DESTDIR)$(pkgdatadir)/HerwigDefaults.rpo; \
 	rm -f $(DESTDIR)$(pkgdatadir)/HerwigDefaults.rpo.bak; \
         fi
 
 uninstall-hook:
 	rm -f $(DESTDIR)$(pkgdatadir)/HerwigDefaults.rpo
 
 
 register: register-with-thepeg-repo
 register-with-thepeg-repo:
 	@if test -x "$(SETUPTHEPEG)" -a -w "$(THEPEGREPO)"; \
 		then echo Registering with ThePEG; \
 		"$(SETUPTHEPEG)" --init \
 		$(DESTDIR)$(defaultsdir)/HerwigDefaults.in \
 		-r "$(THEPEGREPO)" -o "$(THEPEGREPO)" \
 		-i $(DESTDIR)$(pkgdatadir) \
 		-l$(DESTDIR)$(pkglibdir) ; \
 		if test -n "$(DESTDIR)"; \
 		then sed -i -e "s@$(DESTDIR)@@g" "$(THEPEGREPO)" ; fi ; \
 	fi
 
 
 unregister : unregister-from-thepeg-repo
 unregister-from-thepeg-repo:
 	@if test -x "$(SETUPTHEPEG)" -a -w "$(THEPEGREPO)"; \
 		then echo Unregistering with ThePEG; \
 		"$(SETUPTHEPEG)" --init defaults/HerwigCleanup.in \
 		-r "$(THEPEGREPO)" -o "$(THEPEGREPO)" \
 		-l$(DESTDIR)$(pkglibdir) ; \
 	fi
 
 EXTRA_DIST = herwigopts.ggo
 
 nodist_Herwig_SOURCES = hgstamp.inc
 BUILT_SOURCES += hgstamp.inc
 CLEANFILES += hgstamp.inc
 
 HGVERSION := $(shell hg -R $(top_srcdir) parents --template '"Herwig {node|short} ({branch})"' 2> /dev/null || echo \"$(PACKAGE_STRING)\" || true )
 
 .PHONY: update_hgstamp
 hgstamp.inc: update_hgstamp
 	@[ -f $@ ] || touch $@
 	@echo '$(HGVERSION)' | cmp -s $@ - || echo '$(HGVERSION)' > $@
 
 GENGETOPT = gengetopt
 
 %opts.h %opts.c : %opts.ggo
 	$(GENGETOPT) < $<
-