diff --git a/SConstruct b/SConstruct
index 7ad9dd8451..efcff18a8e 100644
--- a/SConstruct
+++ b/SConstruct
@@ -728,7 +728,8 @@ prep_libcheck(env, libraries['flac'])
 libraries['flac'].Append(CCFLAGS="-I/usr/local/include", LINKFLAGS="-L/usr/local/lib")
 
 conf = Configure (libraries['flac'])
-conf.CheckLib ('FLAC', 'FLAC__stream_decoder_new', language='CXX')
+if conf.CheckLib ('FLAC', 'FLAC__stream_decoder_new', language='CXX'):
+    conf.env.Append('-DHAVE_FLAC')
 libraries['flac'] = conf.Finish ()
 
 # or if that fails...
diff --git a/libs/ardour/audiofilesource.cc b/libs/ardour/audiofilesource.cc
index 717ac91e3b..9a3bf266ae 100644
--- a/libs/ardour/audiofilesource.cc
+++ b/libs/ardour/audiofilesource.cc
@@ -565,6 +565,9 @@ AudioFileSource::safe_file_extension(ustring file)
 		file.rfind(".maud")== ustring::npos &&
 		file.rfind(".vwe") == ustring::npos &&
 		file.rfind(".paf") == ustring::npos &&
+#ifdef HAVE_FLAC
+		file.rfind(".flac")== ustring::npos &&
+#endif // HAVE_FLAC
 #ifdef HAVE_COREAUDIO
 		file.rfind(".mp3") == ustring::npos &&
 		file.rfind(".aac") == ustring::npos &&