diff --git a/azurerm/internal/services/web/app_service.go b/azurerm/internal/services/web/app_service.go
index 97224e1cb5e6..5bd7e2cf32e5 100644
--- a/azurerm/internal/services/web/app_service.go
+++ b/azurerm/internal/services/web/app_service.go
@@ -421,10 +421,7 @@ func schemaAppServiceSiteConfig() *schema.Schema {
 						string(web.ScmTypeOneDrive),
 						string(web.ScmTypeTfs),
 						string(web.ScmTypeVSO),
-						// Not in the specs, but is set by Azure Pipelines
-						// https://github.com/Microsoft/azure-pipelines-tasks/blob/master/Tasks/AzureRmWebAppDeploymentV4/operations/AzureAppServiceUtility.ts#L19
-						// upstream issue: https://github.com/Azure/azure-rest-api-specs/issues/5345
-						"VSTSRM",
+						string(web.ScmTypeVSTSRM),
 					}, false),
 				},
 
diff --git a/azurerm/internal/services/web/resource_arm_app_service.go b/azurerm/internal/services/web/resource_arm_app_service.go
index a3570549f6c2..1d6166525f67 100644
--- a/azurerm/internal/services/web/resource_arm_app_service.go
+++ b/azurerm/internal/services/web/resource_arm_app_service.go
@@ -377,6 +377,8 @@ func resourceArmAppServiceUpdate(d *schema.ResourceData, meta interface{}) error
 	// If `source_control` is defined, we need to set site_config.0.scm_type to "None" or we cannot update it
 	_, hasSourceControl := d.GetOk("source_control.0.repo_url")
 
+	scmType := web.ScmTypeNone
+
 	if d.HasChange("site_config") || hasSourceControl {
 		// update the main configuration
 		siteConfig, err := expandAppServiceSiteConfig(d.Get("site_config"))
@@ -387,8 +389,10 @@ func resourceArmAppServiceUpdate(d *schema.ResourceData, meta interface{}) error
 			SiteConfig: siteConfig,
 		}
 
-		if hasSourceControl {
-			siteConfigResource.SiteConfig.ScmType = "None"
+		scmType = siteConfig.ScmType
+		// ScmType being set blocks the update of source_control in _most_ cases, ADO is an exception
+		if hasSourceControl && scmType != web.ScmTypeVSTSRM {
+			siteConfigResource.SiteConfig.ScmType = web.ScmTypeNone
 		}
 
 		if _, err := client.CreateOrUpdateConfiguration(ctx, id.ResourceGroup, id.Name, siteConfigResource); err != nil {
@@ -396,7 +400,8 @@ func resourceArmAppServiceUpdate(d *schema.ResourceData, meta interface{}) error
 		}
 	}
 
-	if hasSourceControl {
+	// Don't send source_control changes for ADO controlled Apps
+	if hasSourceControl && scmType != web.ScmTypeVSTSRM {
 		sourceControlProperties := expandAppServiceSiteSourceControl(d)
 		sourceControl := &web.SiteSourceControl{}
 		sourceControl.SiteSourceControlProperties = sourceControlProperties
diff --git a/azurerm/internal/services/web/resource_arm_function_app.go b/azurerm/internal/services/web/resource_arm_function_app.go
index 062c519f0a94..f7a2b23f50cf 100644
--- a/azurerm/internal/services/web/resource_arm_function_app.go
+++ b/azurerm/internal/services/web/resource_arm_function_app.go
@@ -458,6 +458,8 @@ func resourceArmFunctionAppUpdate(d *schema.ResourceData, meta interface{}) erro
 	// repo_url is required by the API
 	_, hasSourceControl := d.GetOk("source_control.0.repo_url")
 
+	scmType := web.ScmTypeNone
+
 	if d.HasChange("site_config") || hasSourceControl {
 		siteConfig, err := expandFunctionAppSiteConfig(d)
 		if err != nil {
@@ -467,8 +469,10 @@ func resourceArmFunctionAppUpdate(d *schema.ResourceData, meta interface{}) erro
 			SiteConfig: &siteConfig,
 		}
 
-		if hasSourceControl {
-			siteConfigResource.SiteConfig.ScmType = "None"
+		scmType = siteConfig.ScmType
+		// ScmType being set blocks the update of source_control in _most_ cases, ADO is an exception
+		if hasSourceControl && scmType != web.ScmTypeVSTSRM {
+			siteConfigResource.SiteConfig.ScmType = web.ScmTypeNone
 		}
 
 		if _, err := client.CreateOrUpdateConfiguration(ctx, id.ResourceGroup, id.Name, siteConfigResource); err != nil {
@@ -476,7 +480,8 @@ func resourceArmFunctionAppUpdate(d *schema.ResourceData, meta interface{}) erro
 		}
 	}
 
-	if hasSourceControl {
+	// Don't send source_control changes for ADO controlled Apps
+	if hasSourceControl && scmType != web.ScmTypeVSTSRM {
 		sourceControlProperties := expandAppServiceSiteSourceControl(d)
 		sourceControl := &web.SiteSourceControl{}
 		sourceControl.SiteSourceControlProperties = sourceControlProperties