diff --git a/packages/apps/vpc/templates/vpc.yaml b/packages/apps/vpc/templates/vpc.yaml
index cb860279..784c181b 100644
--- a/packages/apps/vpc/templates/vpc.yaml
+++ b/packages/apps/vpc/templates/vpc.yaml
@@ -16,7 +16,6 @@ spec:
   namespaces:
     - {{ .Release.Namespace }}
 {{- if .Values.peers }}
-{{- $hexLookup := dict "0" 0 "1" 1 "2" 2 "3" 3 "4" 4 "5" 5 "6" 6 "7" 7 "8" 8 "9" 9 "a" 10 "b" 11 "c" 12 "d" 13 "e" 14 "f" 15 }}
   vpcPeerings:
 {{- range .Values.peers }}
 {{- $remoteRelease := printf "virtualprivatecloud-%s" .vpcName }}
@@ -24,12 +23,8 @@ spec:
 {{- $sorted := list $vpcId $remoteVpcId | sortAlpha }}
 {{- $pairKey := join "/" $sorted }}
 {{- $pairHash := sha256sum $pairKey }}
-{{- $h0 := int (get $hexLookup (substr 0 1 $pairHash)) }}
-{{- $h1 := int (get $hexLookup (substr 1 2 $pairHash)) }}
-{{- $h2 := int (get $hexLookup (substr 2 3 $pairHash)) }}
-{{- $h3 := int (get $hexLookup (substr 3 4 $pairHash)) }}
-{{- $byte0 := add (mul $h0 16) $h1 }}
-{{- $byte1 := add (mul $h2 16) $h3 }}
+{{- $byte0 := int (include "cozy-lib.strings.hexToInt" (substr 0 2 $pairHash)) }}
+{{- $byte1 := int (include "cozy-lib.strings.hexToInt" (substr 2 4 $pairHash)) }}
 {{- $oct3 := int (add (mod $byte0 254) 1) }}
 {{- $base4 := int (mul (mod $byte1 64) 4) }}
 {{- if eq $vpcId (index $sorted 0) }}
diff --git a/packages/library/cozy-lib/templates/_strings.tpl b/packages/library/cozy-lib/templates/_strings.tpl
new file mode 100644
index 00000000..0ba8153f
--- /dev/null
+++ b/packages/library/cozy-lib/templates/_strings.tpl
@@ -0,0 +1,3 @@
+{{- define "cozy-lib.strings.hexToInt" }}
+{{- printf "num: 0x%s" . | fromYaml | dig "num" 0 }}
+{{- end }}