diff --git a/Makefile b/Makefile
index f6990913c27f9b8ada6b3b75110eac935b45b8fd..891f16ecb3374a81a5c6111feea2b9c64165f71e 100755
--- a/Makefile
+++ b/Makefile
@@ -9,6 +9,6 @@ md: $(OBJS) $(INCS)
 	$(CC) $(CFLAGS) rvec.o md.o md-extra.o -o md -lm
 
 clean:
-	rm -f md
+	rm -f md a.out
 	rm -f *.o
 	rm -f *~
diff --git a/README.md b/README.md
index cd159a48ab292c4b12ddc8bec4f79d0e9f63af1f..56caa413b8f50a08f1ad9974a32436e1077558e3 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,9 @@
 # MD Uebung files
 
 This began life as Nils Uebung.
-In June 2022, I had to move executable code out of `rvec.h`. There was executable code which is not allowed in a `.h` file.
+In June 2022, I moved executable code out of `rvec.h`. There was executable code which is not allowed in a `.h` file.
 
 I also removed some unnecessary lines from the Makefile.
+
+# BUGS
+If you compile with `-Wall`, there will be some warnings about unused variables. These are not a problem. This is an assignment in which one should write code that uses these variables.