diff --git a/2019/karns/Makefile b/2019/karns/Makefile
index 6cb1f6e3f..5677b3f1d 100644
--- a/2019/karns/Makefile
+++ b/2019/karns/Makefile
@@ -114,7 +114,7 @@ PROG= prog
 #
 OBJ= ${PROG}.o
 CSRC= ${PROG}.o
-DATA= maze demo.sh
+DATA= maze try.sh
 TARGET= ${PROG}
 #
 ALT_OBJ=
@@ -141,8 +141,8 @@ ${PROG}: ${PROG}.c
 	${CC} ${CFLAGS} $< -o $@ ${LDFLAGS}
 	${LN} -sf ${PROG} tbfs
 
-test: prog
-	${CAT} prog.c | ./prog
+test: ${PROG}
+	./${PROG} < ${PROG}.c
 
 
 # alternative executable
diff --git a/2019/karns/README.md b/2019/karns/README.md
index df51ddeb5..257946013 100644
--- a/2019/karns/README.md
+++ b/2019/karns/README.md
@@ -26,7 +26,7 @@ The last two can be done in a sequence, first showing the respective files at
 the terminal, like:
 
 ```sh
-./demo.sh
+./try.sh
 ```
 
 
diff --git a/2019/karns/demo.sh b/2019/karns/try.sh
similarity index 62%
rename from 2019/karns/demo.sh
rename to 2019/karns/try.sh
index e70d0f521..e8e02483d 100755
--- a/2019/karns/demo.sh
+++ b/2019/karns/try.sh
@@ -5,8 +5,17 @@
 # Doesn't run the program on README.md as it's longer and slower.
 #
 
-# make prog first and exit if failure
-make || exit
+# make sure CC is set so that when we do make CC="$CC" it isn't empty. Doing it
+# this way allows us to have the user specify a different compiler in an easy
+# way.
+if [[ -z "$CC" ]]; then
+    CC="cc"
+fi
+
+make CC="$CC" all >/dev/null || exit 1
+
+# clear screen after compilation so that only the entry is shown
+clear
 
 # display prog.c to the user
 echo "$ cat prog.c"