diff --git a/src/spek-audio.cc b/src/spek-audio.cc
index e519b9c..f1daebb 100644
--- a/src/spek-audio.cc
+++ b/src/spek-audio.cc
@@ -134,9 +134,12 @@ std::unique_ptr<AudioFile> Audio::open(const std::string& file_name)
         bits_per_sample = codec_context->bits_per_raw_sample;
         if (!bits_per_sample) {
             // APE uses bpcs, FLAC uses bprs.
-            // TODO: old comment, verify
             bits_per_sample = codec_context->bits_per_coded_sample;
         }
+        if (codec_context->codec_id == AV_CODEC_ID_AAC) {
+            // AAC decoder sets both bps and bitrate.
+            bits_per_sample = 0;
+        }
         if (bits_per_sample) {
             bit_rate = 0;
         }
diff --git a/tests/samples/2ch-44100Hz-q100.m4a b/tests/samples/2ch-44100Hz-q100.m4a
new file mode 100644
index 0000000..deae3a1
Binary files /dev/null and b/tests/samples/2ch-44100Hz-q100.m4a differ
diff --git a/tests/test-audio-info.cc b/tests/test-audio-info.cc
index aa55852..196c26b 100644
--- a/tests/test-audio-info.cc
+++ b/tests/test-audio-info.cc
@@ -50,6 +50,7 @@ static void test_file(const std::string& name, const FileInfo& info)
 void test_audio_info()
 {
     const double MP3_T = 5.0 * 1152 / 44100; // 5 frames * duration per mp3 frame
+    const double M4A_T = (10240 + 628) / 2.0 / 44100;
 
     std::map<std::string, FileInfo> files = {
         {"1ch-96000Hz-24bps.flac", {"FLAC", 0, 96000, 24, 1, 0.1}},
@@ -63,6 +64,7 @@ void test_audio_info()
         {"2ch-44100Hz-320cbr.mp3", {"MP3", 320000, 44100, 0, 2, MP3_T}},
         {"2ch-44100Hz-V0.mp3", {"MP3", 201329, 44100, 0, 2, MP3_T}},
         {"2ch-44100Hz-V2.mp3", {"MP3", 150124, 44100, 0, 2, MP3_T}},
+        {"2ch-44100Hz-q100.m4a", {"AAC", 159649, 44100, 0, 2, M4A_T}},
         {"2ch-44100Hz-q5.ogg", {"Vorbis", 160000, 44100, 0, 2, 0.1}},
     };
     for (const auto& item : files) {
diff --git a/tests/test-audio-read.cc b/tests/test-audio-read.cc
index 503515c..c63257c 100644
--- a/tests/test-audio-read.cc
+++ b/tests/test-audio-read.cc
@@ -58,6 +58,7 @@ void test_audio_read()
         {"2ch-44100Hz-320cbr.mp3", 2 * 1152 * 4 + 94},
         {"2ch-44100Hz-V0.mp3", 2 * 1152 * 4 + 94},
         {"2ch-44100Hz-V2.mp3", 2 * 1152 * 4 + 94},
+        {"2ch-44100Hz-q100.m4a", 10240},
         {"2ch-44100Hz-q5.ogg", 2 * 1024 * 4 + 1152},
     };
     for (const auto& item : files) {