diff --git a/calendar/libical/src/libical/Makefile.in b/calendar/libical/src/libical/Makefile.in
index 19d3aee390..8c6cf15b72 100644
--- a/calendar/libical/src/libical/Makefile.in
+++ b/calendar/libical/src/libical/Makefile.in
@@ -179,10 +179,10 @@ PARAMETERDEPS =	\
 	icalderivedparameter.h.in
 
 icalderivedparameter.h: $(PARAMETERDEPS) 
-	$(PERL) -I $(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedparameters.pl -i $(srcdir)/icalderivedparameter.h.in -h $(DESIGNDATA)/parameters.csv > icalderivedparameter.h 
+	$(PERL) -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedparameters.pl -i $(srcdir)/icalderivedparameter.h.in -h $(DESIGNDATA)/parameters.csv > icalderivedparameter.h
 
 icalderivedparameter.c: $(PARAMETERDEPS) $(BUILT_COMBINEDHEADERS)
-	$(PERL) -I $(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedparameters.pl -i $(srcdir)/icalderivedparameter.c.in -c $(DESIGNDATA)/parameters.csv > icalderivedparameter.c
+	$(PERL) -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedparameters.pl -i $(srcdir)/icalderivedparameter.c.in -c $(DESIGNDATA)/parameters.csv > icalderivedparameter.c
 
 # properties
 
@@ -195,12 +195,12 @@ PROPERTYDEPS =					\
 
 
 icalderivedproperty.h: $(PROPERTYDEPS)
-	$(PERL)  -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedproperties.pl \
+	$(PERL) -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedproperties.pl \
 		-i $(srcdir)/icalderivedproperty.h.in -h $(DESIGNDATA)/properties.csv\
 		${DESIGNDATA}/value-types.csv > icalderivedproperty.h 
 
 icalderivedproperty.c: $(PROPERTYDEPS) $(BUILT_COMBINEDHEADERS)
-	$(PERL)  -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedproperties.pl \
+	$(PERL) -I$(ICALSCRIPTS) $(ICALSCRIPTS)/mkderivedproperties.pl \
 		-i $(srcdir)/icalderivedproperty.c.in -c $(DESIGNDATA)/properties.csv \
 		${DESIGNDATA}/value-types.csv > icalderivedproperty.c