diff --git a/backend/Makefile b/backend/Makefile
index 6d69248..fe652fe 100644
--- a/backend/Makefile
+++ b/backend/Makefile
@@ -55,7 +55,7 @@ latest: $(LATEST)
 
 $(BOUNDARIES_DATABASE): $(LATEST) $(SCRIPTS)/boundaries.ini $(SCRIPTS)/boundaries.sql
 	$(dir_guard)
-	$(SCRIPTS)/boundaries.sh $@ $^
+	$(SCRIPTS)/boundaries.sh "$@" "$^"
 
 $(BOUNDARIES_GEOJSON): $(BOUNDARIES_DATABASE) $(SCRIPTS)/boundaries_geojson.sql
 	$(dir_guard)
@@ -81,7 +81,7 @@ pbf: $(PBF_REGIONI) $(PBF_PROVINCE) $(PBF_COMUNI)
 
 $(GPKG_DIR)/%.gpkg: $(PBF_DIR)/%.osm.pbf
 	$(dir_guard)
-	rm -f $(@F)
+	rm -f "$(@F)"
 	ogr2ogr -f GPKG -dsco VERSION=1.2 "$@" "$<" >/dev/null
 
 PBF_FILES = $(wildcard $(PBF_DIR)/*/*.osm.pbf)
diff --git a/backend/scripts/extract_6_province.sh b/backend/scripts/extract_6_province.sh
index 11dd2c6..db40ff8 100755
--- a/backend/scripts/extract_6_province.sh
+++ b/backend/scripts/extract_6_province.sh
@@ -20,6 +20,6 @@ EOF
     osmium extract --overwrite \
         --polygon="$file" \
         --output="$OUTPUT/$name.osm.pbf" \
-        "$OUTPUT"/../regioni/"$parent.osm.pbf"
+        "$OUTPUT/../regioni/$parent.osm.pbf"
 done
 
diff --git a/backend/scripts/extract_8_comuni.sh b/backend/scripts/extract_8_comuni.sh
index 8bb8084..1166b4b 100755
--- a/backend/scripts/extract_8_comuni.sh
+++ b/backend/scripts/extract_8_comuni.sh
@@ -20,5 +20,5 @@ EOF
     osmium extract --overwrite \
         --polygon="$file" \
         --output="$OUTPUT/$name.osm.pbf" \
-        "$OUTPUT"/../province/"$parent.osm.pbf"
+        "$OUTPUT/../province/$parent.osm.pbf"
 done
diff --git a/backend/scripts/topojson.sh b/backend/scripts/topojson.sh
index 8450f5b..b7cf069 100755
--- a/backend/scripts/topojson.sh
+++ b/backend/scripts/topojson.sh
@@ -4,7 +4,7 @@ set -o pipefail
 OUTPUT="$1"
 DATABASE="$2"
 
-sqlite_custom="sqlite3 -bail "$DATABASE""
+sqlite_custom="sqlite3 -bail $DATABASE"
 
 cd "$OUTPUT"
 
@@ -106,9 +106,9 @@ select ref_istat
  where admin_level = 4;
 EOF
 ) |
-while read istat
+while read -r istat
 do
-    cat << EOF | $sqlite_custom | mapshaper -i - -simplify 0.005 -o limits_R_${istat}_provinces.json
+    cat << EOF | $sqlite_custom | mapshaper -i - -simplify 0.005 -o limits_R_"$istat"_provinces.json
 .load mod_spatialite
 select json_object(
          'type', 'FeatureCollection',
@@ -131,8 +131,8 @@ select json_object(
  where reg_istat_code = '$istat' and admin_level = 6
  group by true;
 EOF
-    geo2topo limits_R_${istat}_provinces.json -o limits_R_${istat}_provinces_topo.json
-    mv limits_R_${istat}_provinces{_topo,}.json
+    geo2topo limits_R_"$istat"_provinces.json -o limits_R_"$istat"_provinces_topo.json
+    mv limits_R_"$istat"_provinces{_topo,}.json
 done
 
 
@@ -144,9 +144,9 @@ select ref_istat
  where admin_level = 6;
 EOF
 ) |
-while read istat
+while read -r istat
 do
-    cat << EOF | $sqlite_custom | mapshaper -i - -simplify 5% -o limits_P_${istat}_municipalities.json
+    cat << EOF | $sqlite_custom | mapshaper -i - -simplify 5% -o limits_P_"$istat"_municipalities.json
 .load mod_spatialite
 select json_object(
          'type', 'FeatureCollection',
@@ -169,6 +169,6 @@ select json_object(
  where pro_istat_code = '$istat' and admin_level = 8
  group by true;
 EOF
-    geo2topo limits_P_${istat}_municipalities.json -o limits_P_${istat}_municipalities_topo.json
-    mv limits_P_${istat}_municipalities{_topo,}.json
+    geo2topo limits_P_"$istat"_municipalities.json -o limits_P_"$istat"_municipalities_topo.json
+    mv limits_P_"$istat"_municipalities{_topo,}.json
 done