diff --git a/tests/Makefile b/tests/Makefile
index 398651995a..f54f76f1a8 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -20,7 +20,7 @@ test-server: vsynth1/0.pgm asynth1.sw
 	@$(SRC_PATH)/tests/server-regression.sh $(SERVER_REFFILE) $(SRC_PATH)/tests/test.conf
 
 # fast regression tests for all codecs
-test mpeg4 mpeg: vsynth1/0.pgm vsynth2/0.pgm asynth1.sw tiny_psnr
+test mpeg4 mpeg ac3: vsynth1/0.pgm vsynth2/0.pgm asynth1.sw tiny_psnr
 	@$(SRC_PATH)/tests/regression.sh $@ $(REFFILE1) vsynth1
 	@$(SRC_PATH)/tests/regression.sh $@ $(REFFILE2) vsynth2