diff --git a/core/classes/predicate/predicate-tests.factor b/core/classes/predicate/predicate-tests.factor
new file mode 100644
index 0000000000..9f3b3e2141
--- /dev/null
+++ b/core/classes/predicate/predicate-tests.factor
@@ -0,0 +1,14 @@
+USING: math tools.test ;
+IN: classes.predicate
+
+PREDICATE: negative < integer 0 < ;
+PREDICATE: positive < integer 0 > ;
+
+GENERIC: abs ( n -- n )
+M: integer abs ;
+M: negative abs -1 * ;
+M: positive abs ;
+
+[ 10 ] [ -10 abs ] unit-test
+[ 10 ] [ 10 abs ] unit-test
+[ 0 ] [ 0 abs ] unit-test