diff --git a/jni/android_hardware_fm.cpp b/jni/android_hardware_fm.cpp
index 5cb7318..628559c 100644
--- a/jni/android_hardware_fm.cpp
+++ b/jni/android_hardware_fm.cpp
@@ -128,7 +128,7 @@
 static bool mCallbacksObjCreated = false;
 static jfieldID sCallbacksField;
 
-jclass javaClassRef;
+static jclass javaClassRef;
 static jmethodID method_psInfoCallback;
 static jmethodID method_rtCallback;
 static jmethodID method_ertCallback;