diff --git a/internal/services/appservice/helpers/linux_web_app_schema.go b/internal/services/appservice/helpers/linux_web_app_schema.go
index 3e57ebc42377..102e8c09946a 100644
--- a/internal/services/appservice/helpers/linux_web_app_schema.go
+++ b/internal/services/appservice/helpers/linux_web_app_schema.go
@@ -888,6 +888,7 @@ func (s *SiteConfigLinux) ExpandForCreate(appSettings map[string]string) (*webap
 func (s *SiteConfigLinux) ExpandForUpdate(metadata sdk.ResourceMetaData, existing *webapps.SiteConfig, appSettings map[string]string) (*webapps.SiteConfig, error) {
 	expanded := *existing
 
+	expanded.AlwaysOn = pointer.To(s.AlwaysOn)
 	expanded.AcrUseManagedIdentityCreds = pointer.To(s.UseManagedIdentityACR)
 	expanded.AutoHealEnabled = pointer.To(s.AutoHeal)
 	expanded.HTTP20Enabled = pointer.To(s.Http2Enabled)
diff --git a/internal/services/appservice/helpers/web_app_slot_schema.go b/internal/services/appservice/helpers/web_app_slot_schema.go
index d74bfee62789..c9124da50930 100644
--- a/internal/services/appservice/helpers/web_app_slot_schema.go
+++ b/internal/services/appservice/helpers/web_app_slot_schema.go
@@ -678,6 +678,7 @@ func (s *SiteConfigLinuxWebAppSlot) ExpandForCreate(appSettings map[string]strin
 func (s *SiteConfigLinuxWebAppSlot) ExpandForUpdate(metadata sdk.ResourceMetaData, existing *webapps.SiteConfig, appSettings map[string]string) (*webapps.SiteConfig, error) {
 	expanded := *existing
 
+	expanded.AlwaysOn = pointer.To(s.AlwaysOn)
 	expanded.AcrUseManagedIdentityCreds = pointer.To(s.UseManagedIdentityACR)
 	expanded.AutoHealEnabled = pointer.To(s.AutoHeal)
 	expanded.HTTP20Enabled = pointer.To(s.Http2Enabled)