diff --git a/runtime/vm/interpreter.cc b/runtime/vm/interpreter.cc
index 1ce3b76..0f2cea1 100644
--- a/runtime/vm/interpreter.cc
+++ b/runtime/vm/interpreter.cc
@@ -1038,7 +1038,9 @@
           }
         }
       }
-      reinterpret_cast<RawObject**>(instance->ptr())[offset_in_words] = value;
+      instance->StorePointer(
+          reinterpret_cast<RawObject**>(instance->ptr()) + offset_in_words,
+          value);
       *SP = call_base;
       **SP = null_value;
       *invoked = true;