diff --git a/eos-s3/btn_counter/Makefile b/eos-s3/btn_counter/Makefile
index dd1658a..fece24e 100644
--- a/eos-s3/btn_counter/Makefile
+++ b/eos-s3/btn_counter/Makefile
@@ -1,7 +1,11 @@
 ifdef F4PGA_USE_DEPRECATED
 all:
-	ql_symbiflow \
-	  -compile \
+# -d: Device
+# -P: Part name
+# -v: Verilog source
+# -t: Top
+# -p: PCF Constrains
+	ql_symbiflow -compile \
 	  -d ql-eos-s3 \
 	  -P PD64 \
 	  -v btn_counter.v \