diff --git a/src/wav.c b/src/wav.c
index 12c0c254..0dd6c730 100644
--- a/src/wav.c
+++ b/src/wav.c
@@ -207,6 +207,14 @@ wav_open	(SF_PRIVATE *psf)
 			psf->sf.frames = 0 ;
 			} ;
 
+#if (ENABLE_EXPERIMENTAL_CODE == 0)
+		/* For now, don't support writing MPEGLAYER3 WAVs, as we can't guarentee that
+		** such a file written by libsndfile would have the same length when opened again.
+		*/
+		if (subformat == SF_FORMAT_MPEG_LAYER_III)
+			return SFE_UNSUPPORTED_ENCODING ;
+#endif
+
 		if (subformat == SF_FORMAT_IMA_ADPCM || subformat == SF_FORMAT_MS_ADPCM)
 		{	blockalign = wavlike_srate2blocksize (psf->sf.samplerate * psf->sf.channels) ;
 			framesperblock = -1 ; /* Corrected later. */
@@ -944,6 +952,7 @@ wav_write_fmt_chunk (SF_PRIVATE *psf)
 					add_fact_chunk = SF_TRUE ;
 					break ;
 
+#if (ENABLE_EXPERIMENTAL_CODE == 0)
 		case SF_FORMAT_MPEG_LAYER_III :
 					{	int bytespersec, blockalign, flags, blocksize, samplesperblock, codecdelay ;
 
@@ -994,6 +1003,7 @@ wav_write_fmt_chunk (SF_PRIVATE *psf)
 
 					add_fact_chunk = SF_TRUE ;
 					break ;
+#endif
 
 		default : 	return SFE_UNIMPLEMENTED ;
 		} ;
diff --git a/tests/format_check_test.c b/tests/format_check_test.c
index eda557a4..2e76679a 100644
--- a/tests/format_check_test.c
+++ b/tests/format_check_test.c
@@ -126,6 +126,11 @@ format_combo_test (void)
 					subtype_fmt_info.format == SF_FORMAT_MPEG_LAYER_II)
 				continue ;
 
+			/* MPEG Layer III in WAV is decode only currently */
+			if (subtype_fmt_info.format == SF_FORMAT_MPEG_LAYER_III &&
+					major_fmt_info.format == SF_FORMAT_WAV)
+				continue ;
+
 			snprintf (filename, sizeof (filename), "format-check.%s", major_fmt_info.extension) ;
 
 			sndfile = sf_open (filename, SFM_WRITE, &info) ;