diff --git a/inc/Runtime/MountedRuntimeBootstrap.php b/inc/Runtime/MountedRuntimeBootstrap.php
index 8e58e98..6f434bb 100644
--- a/inc/Runtime/MountedRuntimeBootstrap.php
+++ b/inc/Runtime/MountedRuntimeBootstrap.php
@@ -185,10 +185,11 @@ public static function adopt_workspace_mounts(): void {
 				continue;
 			}
 
+			$workspace_ref = (string) ( $mount['workspace_ref'] ?? '' );
 			WorkspaceAbilities::adoptRepo(
 				array(
 					'path' => $path,
-					'name' => basename($path),
+					'name' => '' !== $workspace_ref ? $workspace_ref : basename($path),
 				)
 			);
 		}
@@ -207,7 +208,7 @@ private static function workspace_root_from_context( array $context ): string {
 
 	/**
 	 * @param array<string,mixed> $context
-	 * @return array<int,array{path:string,repo_backed:bool}>
+	 * @return array<int,array{path:string,repo_backed:bool,workspace_ref?:string}>
 	 */
 	private static function workspace_mounts( array $context, string $workspace_root ): array {
 		$workspace = self::runtime_workspace_from_context($context);
@@ -221,9 +222,14 @@ private static function workspace_mounts( array $context, string $workspace_root
 				if ( '' === $target || 0 !== strpos($target . '/', $workspace_root . '/') ) {
 					continue;
 				}
-				$mounts[] = array(
-					'path'        => $target,
-					'repo_backed' => 'repo-backed' === (string) ( $mount['sourceMode'] ?? '' ),
+				$workspace_ref = trim( (string) ( $mount['workspaceRef'] ?? '' ) );
+				$mounts[]      = array_filter(
+					array(
+						'path'          => $target,
+						'repo_backed'   => 'repo-backed' === (string) ( $mount['sourceMode'] ?? '' ),
+						'workspace_ref' => $workspace_ref,
+					),
+					static fn ( $value ): bool => '' !== $value
 				);
 			}
 		}
diff --git a/tests/mounted-runtime-context.php b/tests/mounted-runtime-context.php
index b5ccc50..54b6a7a 100644
--- a/tests/mounted-runtime-context.php
+++ b/tests/mounted-runtime-context.php
@@ -55,6 +55,29 @@ function mounted_runtime_context_assert_same( mixed $expected, mixed $actual, st
 
 mounted_runtime_context_assert_same('/tmp/legacy-mounted-workspace', $context['runtime_workspace']['root'] ?? '', 'Deprecated sandbox workspace input is normalized to runtime workspace.');
 
+$method = new ReflectionMethod(MountedRuntimeBootstrap::class, 'workspace_mounts');
+
+$mounts = $method->invoke(
+	null,
+	array(
+		'runtime_workspace' => array(
+			'root'   => '/tmp/mounted-workspace',
+			'mounts' => array(
+				array(
+					'target'       => '/tmp/mounted-workspace/wp-site-generator',
+					'sourceMode'   => 'mounted',
+					'workspaceRef' => 'wp-site-generator@wpsg-lab-proof-20260622-2102',
+				),
+			),
+		),
+	),
+	'/tmp/mounted-workspace'
+);
+
+mounted_runtime_context_assert_same('wp-site-generator@wpsg-lab-proof-20260622-2102', $mounts[0]['workspace_ref'] ?? '', 'Mounted workspace adoption preserves the full worktree handle.');
+
+$method = new ReflectionMethod(MountedRuntimeBootstrap::class, 'discover_context');
+
 $GLOBALS['wordpress_runtime_context'] = array( 'workspace_root' => '/tmp/generic-wordpress-workspace' );
 $context                              = $method->invoke(null);
 unset($GLOBALS['wordpress_runtime_context']);