diff --git a/templates/_helpers.tpl b/templates/_helpers.tpl
index 45e7a28..30ee3b9 100644
--- a/templates/_helpers.tpl
+++ b/templates/_helpers.tpl
@@ -40,7 +40,7 @@ Create image name and tag used by the deployment.
 {{- $registry := .Values.global.imageRegistry | default .Values.image.registry -}}
 {{- $repository := .Values.image.repository -}}
 {{- $separator := ":" -}}
-{{- $tag := .Values.image.tag | default .Chart.AppVersion -}}
+{{- $tag := .Values.image.tag | default .Chart.AppVersion | toString -}}
 {{- $rootless := ternary "-rootless" "" (.Values.image.rootless) -}}
 {{- $digest := "" -}}
 {{- if .Values.image.digest }}
diff --git a/unittests/deployment/image-configuration.yaml b/unittests/deployment/image-configuration.yaml
index 35f8981..7b1e146 100644
--- a/unittests/deployment/image-configuration.yaml
+++ b/unittests/deployment/image-configuration.yaml
@@ -91,3 +91,20 @@ tests:
       - equal:
           path: spec.template.spec.containers[0].image
           value: "global.example.com/gitea/gitea:1.19.3-rootless@sha256:b28e8f3089b52ebe6693295df142f8c12eff354e9a4a5bfbb5c10f296c3a537a"
+  - it: correctly renders floating tag references
+    template: templates/gitea/deployment.yaml
+    set:
+      image.tag: 1.21 # use non-quoted value on purpose. See: https://gitea.com/gitea/helm-chart/issues/631
+    asserts:
+      - equal:
+          path: spec.template.spec.initContainers[0].image
+          value: "gitea/gitea:1.21-rootless"
+      - equal:
+          path: spec.template.spec.initContainers[1].image
+          value: "gitea/gitea:1.21-rootless"
+      - equal:
+          path: spec.template.spec.initContainers[2].image
+          value: "gitea/gitea:1.21-rootless"
+      - equal:
+          path: spec.template.spec.containers[0].image
+          value: "gitea/gitea:1.21-rootless"