--- a/libs/ardour/port_manager.cc
+++ b/libs/ardour/port_manager.cc
@@ -80,7 +80,7 @@
 			_cfg_db_s  = Config->get_meter_falloff ();
 			_n_samples = n_samples;
 			_rate      = rate;
-#ifdef _GNU_SOURCE
+#if defined _GNU_SOURCE && !defined __ANDROID__
 			_falloff = exp10f (-0.05f * _cfg_db_s * _n_samples / _rate);
 #else
 			_falloff = powf (10.f, -0.05f * _cfg_db_s * _n_samples / _rate);