diff --git a/lalapps/src/string/Makefile.S5pipeline b/lalapps/src/string/Makefile.S5pipeline
index bf54ca57bea89ba19ce802597fde9d75d0ca88ee..e77e074081b2107f3a0993d3006d0e7a3f29457c 100644
--- a/lalapps/src/string/Makefile.S5pipeline
+++ b/lalapps/src/string/Makefile.S5pipeline
@@ -2,10 +2,10 @@ dag :
 	ligolw_segments --verbose --coalesce --comment "S5 string cusp search" --name vetoes --insert-from-segwizard H1=S5-H1-cat2.txt --insert-from-segwizard H2=S5-H2-cat2.txt --insert-from-segwizard L1=S5-L1-cat2.txt --insert-from-segwizard V1=S5-V1-cat2.txt --output vetoes.xml.gz
 	lalapps_gen_timeslides --verbose --instrument H1=0:0:0 --instrument H2=10.634723105433096:10.634723105433096:0 --instrument L1=85.077784843464755:85.077784843464755:0 --instrument V1=-74.443061738031659:-74.443061738031659:0 injection_time_slides.xml.gz
 	lalapps_gen_timeslides --verbose --instrument H1=0:0:0 --instrument H2=0:0:0 --instrument L1=-70.898154036220632:+70.898154036220632:3.5449077018110318 --instrument V1=-70.898154036220632:+70.898154036220632:3.5449077018110318 background_time_slides_0.xml.gz
-	n=1 ; while [[ $$n -le 18 ]] ; do \
+	n=1 ; while [ $$n -le 18 ] ; do \
 	    ligolw_segments --verbose --coalesce --comment "S5 string cusp search chunk $$n" --name segments --insert-from-segwizard H1=segments/S5-H1segments-cat1_c$$n.txt --insert-from-segwizard H2=segments/S5-H2segments-cat1_c$$n.txt --insert-from-segwizard L1=segments/S5-L1segments-cat1_c$$n.txt --insert-from-segwizard V1=segments/S5-V1segments-cat1_c$$n.txt --output segments_c$$n.xml.gz ; \
 	    mkdir -p dag_c$$n ; pushd dag_c$$n ; lalapps_cosmicstring_pipe --verbose --config-file ../S5_StringDag.ini --log-path $(TMPDIR) --segments-file ../segments_c$$n.xml.gz --vetoes-file ../vetoes.xml.gz --injection-time-slides ../injection_time_slides.xml.gz --background-time-slides ../background_time_slides_0.xml.gz ; popd ; \
-	    ((n = n + 1)) ; \
+	    n=$$(($$n + 1)) ; \
 	done 
 
 clean :
diff --git a/lalapps/src/string/Makefile.S6pipeline b/lalapps/src/string/Makefile.S6pipeline
index ee058565bcadf94d3ae4c36eb7fafad95cdc6092..4a545caf0fe249793972e526dc67bad0517af731 100644
--- a/lalapps/src/string/Makefile.S6pipeline
+++ b/lalapps/src/string/Makefile.S6pipeline
@@ -2,10 +2,10 @@ dag :
 	ligolw_segments --verbose --coalesce --comment "S6 string cusp search" --name vetoes --insert-from-segwizard H1=S6-H1-cat2.txt --insert-from-segwizard L1=S6-L1-cat2.txt --insert-from-segwizard V1=S6-V1-cat2.txt --output S6vetoes.xml.gz
 	lalapps_gen_timeslides --verbose --instrument H1=0:0:0 --instrument L1=85.077784843464755:85.077784843464755:0 --instrument V1=-74.443061738031659:-74.443061738031659:0 S6injection_time_slides.xml.gz
 	lalapps_gen_timeslides --verbose --instrument H1=0:0:0 --instrument L1=-70.898154036220632:+70.898154036220632:3.5449077018110318 --instrument V1=-70.898154036220632:+70.898154036220632:3.5449077018110318 S6background_time_slides_0.xml.gz
-	n=20 ; while [[ $$n -le 25 ]] ; do \
+	n=20 ; while [ $$n -le 25 ] ; do \
 	    ligolw_segments --verbose --coalesce --comment "S6 string cusp search chunk $$n" --name segments --insert-from-segwizard H1=segments/S6-H1segments-cat1_c$$n.txt --insert-from-segwizard L1=segments/S6-L1segments-cat1_c$$n.txt --insert-from-segwizard V1=segments/S6-V1segments-cat1_c$$n.txt --output S6segments_c$$n.xml.gz ; \
 	    mkdir -p dag_c$$n ; pushd dag_c$$n ; lalapps_cosmicstring_pipe --verbose --config-file ../S6_StringDag.ini --log-path $(TMPDIR) --segments-file ../S6segments_c$$n.xml.gz --vetoes-file ../S6vetoes.xml.gz --injection-time-slides ../S6injection_time_slides.xml.gz --background-time-slides ../S6background_time_slides_0.xml.gz ; popd ; \
-	    ((n = n + 1)) ; \
+	    n=$$(($$n + 1)) ; \
 	done 
 
 clean :