diff --git a/internal/services/appservice/helpers/web_app_schema.go b/internal/services/appservice/helpers/web_app_schema.go
index ea76859b4563..91b132809d01 100644
--- a/internal/services/appservice/helpers/web_app_schema.go
+++ b/internal/services/appservice/helpers/web_app_schema.go
@@ -2790,8 +2790,9 @@ func ExpandSiteConfigWindows(siteConfig []SiteConfigWindows, existing *web.SiteC
 		if winAppStack.DockerContainerName != "" {
 			if winAppStack.DockerContainerRegistry != "" {
 				expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s/%s:%s", winAppStack.DockerContainerRegistry, winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
+			} else {
+				expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s:%s", winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
 			}
-			expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s:%s", winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
 		}
 		currentStack = winAppStack.CurrentStack
 	}
diff --git a/internal/services/appservice/helpers/web_app_slot_schema.go b/internal/services/appservice/helpers/web_app_slot_schema.go
index e23d66d17e6e..0ebd31d90d64 100644
--- a/internal/services/appservice/helpers/web_app_slot_schema.go
+++ b/internal/services/appservice/helpers/web_app_slot_schema.go
@@ -832,8 +832,9 @@ func ExpandSiteConfigWindowsWebAppSlot(siteConfig []SiteConfigWindowsWebAppSlot,
 		if winAppStack.DockerContainerName != "" {
 			if winAppStack.DockerContainerRegistry != "" {
 				expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s/%s:%s", winAppStack.DockerContainerRegistry, winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
+			} else {
+				expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s:%s", winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
 			}
-			expanded.WindowsFxVersion = utils.String(fmt.Sprintf("DOCKER|%s:%s", winAppStack.DockerContainerName, winAppStack.DockerContainerTag))
 		}
 		currentStack = winAppStack.CurrentStack
 	}