diff --git a/tests/66_printf_undefined.c b/tests/66_printf_undefined.c
new file mode 100644
index 0000000..a1723e9
--- /dev/null
+++ b/tests/66_printf_undefined.c
@@ -0,0 +1,11 @@
+#include <stdio.h>
+
+void fred()
+{
+    printf("test\n");
+}
+
+void main() 
+{
+    fred();
+}
diff --git a/tests/66_printf_undefined.expect b/tests/66_printf_undefined.expect
new file mode 100644
index 0000000..9daeafb
--- /dev/null
+++ b/tests/66_printf_undefined.expect
@@ -0,0 +1 @@
+test
diff --git a/tests/Makefile b/tests/Makefile
index 7c54a66..4448bf9 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -59,7 +59,7 @@ TESTS=	00_assignment.test \
 	62_float.test \
 	63_typedef.test \
 	64_double_prefix_op.test \
-	#65_typeless.test \
+	66_printf_undefined.test \
 
 
 include csmith/Makefile