diff --git a/media/libnbaio/MonoPipe.cpp b/media/libnbaio/MonoPipe.cpp
index c426efb..bbdc8c1 100644
--- a/media/libnbaio/MonoPipe.cpp
+++ b/media/libnbaio/MonoPipe.cpp
@@ -163,6 +163,9 @@
         if (nowTsValid && mWriteTsValid) {
             time_t sec = nowTs.tv_sec - mWriteTs.tv_sec;
             long nsec = nowTs.tv_nsec - mWriteTs.tv_nsec;
+            ALOGE_IF(sec < 0 || (sec == 0 && nsec < 0),
+                    "clock_gettime(CLOCK_MONOTONIC) failed: was %ld.%09ld but now %ld.%09ld",
+                    mWriteTs.tv_sec, mWriteTs.tv_nsec, nowTs.tv_sec, nowTs.tv_nsec);
             if (nsec < 0) {
                 --sec;
                 nsec += 1000000000;
diff --git a/services/audioflinger/FastMixer.cpp b/services/audioflinger/FastMixer.cpp
index 13003d9..3c8a256 100644
--- a/services/audioflinger/FastMixer.cpp
+++ b/services/audioflinger/FastMixer.cpp
@@ -454,6 +454,9 @@
             if (oldTsValid) {
                 time_t sec = newTs.tv_sec - oldTs.tv_sec;
                 long nsec = newTs.tv_nsec - oldTs.tv_nsec;
+                ALOGE_IF(sec < 0 || (sec == 0 && nsec < 0),
+                        "clock_gettime(CLOCK_MONOTONIC) failed: was %ld.%09ld but now %ld.%09ld",
+                        oldTs.tv_sec, oldTs.tv_nsec, newTs.tv_sec, newTs.tv_nsec);
                 if (nsec < 0) {
                     --sec;
                     nsec += 1000000000;