diff --git a/dlls/d3d8/vertexdeclaration.c b/dlls/d3d8/vertexdeclaration.c
index d0e733b9e37..e63e379444e 100644
--- a/dlls/d3d8/vertexdeclaration.c
+++ b/dlls/d3d8/vertexdeclaration.c
@@ -319,9 +319,7 @@ void d3d8_vertex_declaration_destroy(struct d3d8_vertex_declaration *declaration
 {
     TRACE("declaration %p.\n", declaration);
 
-    wined3d_mutex_lock();
     wined3d_vertex_declaration_decref(declaration->wined3d_vertex_declaration);
-    wined3d_mutex_unlock();
 }
 
 static const struct wined3d_parent_ops d3d8_vertexdeclaration_wined3d_parent_ops =