diff --git a/include/media/AudioParameter.h b/include/media/AudioParameter.h
index 79d5d82..8cb2fa7 100644
--- a/include/media/AudioParameter.h
+++ b/include/media/AudioParameter.h
@@ -40,12 +40,12 @@
     //  keyFrameCount: to change audio output frame count, value is an int
     //  keyInputSource: to change audio input source, value is an int in audio_source_t
     //     (defined in media/mediarecorder.h)
-    static const char *keyRouting;
-    static const char *keySamplingRate;
-    static const char *keyFormat;
-    static const char *keyChannels;
-    static const char *keyFrameCount;
-    static const char *keyInputSource;
+    static const char * const keyRouting;
+    static const char * const keySamplingRate;
+    static const char * const keyFormat;
+    static const char * const keyChannels;
+    static const char * const keyFrameCount;
+    static const char * const keyInputSource;
 
     String8 toString();
 
diff --git a/media/libmedia/AudioParameter.cpp b/media/libmedia/AudioParameter.cpp
index abc7b3f..9766ee6 100644
--- a/media/libmedia/AudioParameter.cpp
+++ b/media/libmedia/AudioParameter.cpp
@@ -19,16 +19,18 @@
 
 #include <utils/Log.h>
 
+#include <hardware/audio.h>
 #include <media/AudioParameter.h>
 
 namespace android {
 
-const char *AudioParameter::keyRouting = "routing";
-const char *AudioParameter::keySamplingRate = "sampling_rate";
-const char *AudioParameter::keyFormat = "format";
-const char *AudioParameter::keyChannels = "channels";
-const char *AudioParameter::keyFrameCount = "frame_count";
-const char *AudioParameter::keyInputSource = "input_source";
+// static
+const char * const AudioParameter::keyRouting = AUDIO_PARAMETER_STREAM_ROUTING;
+const char * const AudioParameter::keySamplingRate = AUDIO_PARAMETER_STREAM_SAMPLING_RATE;
+const char * const AudioParameter::keyFormat = AUDIO_PARAMETER_STREAM_FORMAT;
+const char * const AudioParameter::keyChannels = AUDIO_PARAMETER_STREAM_CHANNELS;
+const char * const AudioParameter::keyFrameCount = AUDIO_PARAMETER_STREAM_FRAME_COUNT;
+const char * const AudioParameter::keyInputSource = AUDIO_PARAMETER_STREAM_INPUT_SOURCE;
 
 AudioParameter::AudioParameter(const String8& keyValuePairs)
 {