diff --git a/templates/server-statefulset.yaml b/templates/server-statefulset.yaml
index 9a0097e..0a6c32b 100644
--- a/templates/server-statefulset.yaml
+++ b/templates/server-statefulset.yaml
@@ -1,5 +1,5 @@
 # StatefulSet to run the actual Consul server cluster.
-{{- if (default .Values.server.enabled .Values.global.enabled) }}
+{{- if (or (and (ne (.Values.server.enabled | toString) "-") .Values.server.enabled) (and (eq (.Values.server.enabled | toString) "-") .Values.global.enabled)) }}
 apiVersion: apps/v1
 kind: StatefulSet
 metadata:
diff --git a/test/unit/server-statefulset.bats b/test/unit/server-statefulset.bats
new file mode 100755
index 0000000..e8b1c7a
--- /dev/null
+++ b/test/unit/server-statefulset.bats
@@ -0,0 +1,69 @@
+#!/usr/bin/env bats
+
+load _helpers
+
+@test "server/StatefulSet: enabled by default" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      . | tee /dev/stderr |
+      yq 'length > 0' | tee /dev/stderr)
+  [ "${actual}" = "true" ]
+}
+
+@test "server/StatefulSet: enable with global.enabled false" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      --set 'global.enabled=false' \
+      --set 'server.enabled=true' \
+      . | tee /dev/stderr |
+      yq 'length > 0' | tee /dev/stderr)
+  [ "${actual}" = "true" ]
+}
+
+@test "server/StatefulSet: disable with server.enabled" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      --set 'server.enabled=false' \
+      . | tee /dev/stderr |
+      yq 'length > 0' | tee /dev/stderr)
+  [ "${actual}" = "false" ]
+}
+
+@test "server/StatefulSet: disable with global.enabled" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      --set 'global.enabled=false' \
+      . | tee /dev/stderr |
+      yq 'length > 0' | tee /dev/stderr)
+  [ "${actual}" = "false" ]
+}
+
+@test "server/StatefulSet: no updateStrategy when not updating" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      . | tee /dev/stderr |
+      yq -r '.spec.updateStrategy' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/StatefulSet: updateStrategy during update" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      --set 'server.updatePartition=2' \
+      . | tee /dev/stderr |
+      yq -r '.spec.updateStrategy.type' | tee /dev/stderr)
+  [ "${actual}" = "RollingUpdate" ]
+
+  local actual=$(helm template \
+      -x templates/server-statefulset.yaml  \
+      --set 'server.updatePartition=2' \
+      . | tee /dev/stderr |
+      yq -r '.spec.updateStrategy.rollingUpdate.partition' | tee /dev/stderr)
+  [ "${actual}" = "2" ]
+}