diff --git a/ALACEncoderX.h b/ALACEncoderX.h
index 0a4d9d68..a4929861 100644
--- a/ALACEncoderX.h
+++ b/ALACEncoderX.h
@@ -40,6 +40,22 @@ class ALACEncoderX: public IEncoder, public IEncoderStat {
     uint64_t framesWritten() const { return m_stat.framesWritten(); }
     double currentBitrate() const { return m_stat.currentBitrate(); }
     double overallBitrate() const { return m_stat.overallBitrate(); }
+
+    static bool isAvailableOutputChannelLayout(uint32_t channel_layout_tag)
+    {
+        switch (channel_layout_tag) {
+        case kAudioChannelLayoutTag_Mono:
+        case kAudioChannelLayoutTag_Stereo:
+        case kAudioChannelLayoutTag_AAC_3_0:
+        case kAudioChannelLayoutTag_AAC_4_0:
+        case kAudioChannelLayoutTag_AAC_5_0:
+        case kAudioChannelLayoutTag_AAC_5_1:
+        case kAudioChannelLayoutTag_AAC_6_1:
+        case kAudioChannelLayoutTag_AAC_7_1:
+            return true;
+        }
+        return false;
+    }
 };
 
 #endif
diff --git a/main.cpp b/main.cpp
index 43c01401..065730f5 100644
--- a/main.cpp
+++ b/main.cpp
@@ -529,19 +529,8 @@ void build_filter_chain_sub(std::shared_ptr<ISeekableSource> src,
         }
 #endif
 #ifdef REFALAC
-        switch (*channel_layout) {
-        case kAudioChannelLayoutTag_Mono:
-        case kAudioChannelLayoutTag_Stereo:
-        case kAudioChannelLayoutTag_AAC_3_0:
-        case kAudioChannelLayoutTag_AAC_4_0:
-        case kAudioChannelLayoutTag_AAC_5_0:
-        case kAudioChannelLayoutTag_AAC_5_1:
-        case kAudioChannelLayoutTag_AAC_6_1:
-        case kAudioChannelLayoutTag_AAC_7_1:
-            break;
-        default:
+        if (!ALACEncoderX::isAvailableOutputChannelLayout(*channel_layout))
             throw std::runtime_error("Not supported channel layout for ALAC");
-        }
 #endif
     }
     if (opts.lowpass > 0) {