diff --git a/jni/android_hardware_fm.cpp b/jni/android_hardware_fm.cpp
index c7d4463..bdaceae 100644
--- a/jni/android_hardware_fm.cpp
+++ b/jni/android_hardware_fm.cpp
@@ -408,6 +408,7 @@
             return;
         }
         vm->DetachCurrentThread();
+        mCallbackEnv = NULL;
     }
 }