diff --git a/services/audioflinger/FastMixerDumpState.h b/services/audioflinger/FastMixerDumpState.h
index 81c4175..69c2e4e 100644
--- a/services/audioflinger/FastMixerDumpState.h
+++ b/services/audioflinger/FastMixerDumpState.h
@@ -20,6 +20,7 @@
 #include <stdint.h>
 #include <string>
 #include <audio_utils/TimestampVerifier.h>
+#include <json/json.h>
 #include "Configuration.h"
 #include "FastThreadDumpState.h"
 #include "FastMixerState.h"
@@ -67,7 +68,7 @@
     /*virtual*/ ~FastMixerDumpState();
 
     void dump(int fd) const;             // should only be called on a stable copy, not the original
-    std::string getJsonString() const;   // should only be called on a stable copy, not the original
+    Json::Value getJsonDump() const;     // should only be called on a stable copy, not the original
 
     double   mLatencyMs = 0.;   // measured latency, default of 0 if no valid timestamp read.
     uint32_t mWriteSequence;    // incremented before and after each write()