diff --git a/src/core/lib/promise/context.h b/src/core/lib/promise/context.h
index 3ca2f7bc2e9..0c7930c843c 100644
--- a/src/core/lib/promise/context.h
+++ b/src/core/lib/promise/context.h
@@ -46,7 +46,7 @@ class Context : public ContextType<T> {
   T* const old_;
 
   static T** GetCurrent() {
-    static thread_local T* current;
+    static thread_local T* current = nullptr;
     return &current;
   }
 };