diff --git a/exercises/practice/sum-of-multiples/.meta/sum_of_multiples.example.pl b/exercises/practice/sum-of-multiples/.meta/sum_of_multiples.example.pl
index 87f72090..bc49b9b9 100644
--- a/exercises/practice/sum-of-multiples/.meta/sum_of_multiples.example.pl
+++ b/exercises/practice/sum-of-multiples/.meta/sum_of_multiples.example.pl
@@ -1,14 +1,12 @@
-factored([Curr|Factors], Num) :-
-    0 is mod(Num, Curr), !;
-    factored(Factors, Num).
+:- use_module(library(clpfd)).
 
-sum_of_multiples(_, 0, 0) :- !.
 sum_of_multiples(Factors, Limit, Sum) :-
-    Next is Limit - 1,
-    sum_of_multiples(Factors, Next, NextSum),
-    (
-        factored(Factors, Limit),
-        Sum is Limit + NextSum, !;
-        Sum is NextSum
-    ).
-
+    findall(Multiple, multiple(Factors, Limit, Multiple), Multiples),
+    list_to_set(Multiples, UniqueMultiples),
+    sum_list(UniqueMultiples, Sum).
+    
+multiple(Factors, Limit, Multiple) :-
+    Upper #= Limit - 1,
+    between(0, Upper, Multiple),
+    member(Factor, Factors),
+    Multiple rem Factor #= 0.
diff --git a/exercises/practice/sum-of-multiples/sum_of_multiples_tests.plt b/exercises/practice/sum-of-multiples/sum_of_multiples_tests.plt
index 0250e291..df97fa16 100644
--- a/exercises/practice/sum-of-multiples/sum_of_multiples_tests.plt
+++ b/exercises/practice/sum-of-multiples/sum_of_multiples_tests.plt
@@ -11,36 +11,47 @@ pending :-
         Result == 0.
 
     test(just_one_multiple, condition(pending)) :-
-        sum_of_multiples([3, 5], 4, 3).
+        sum_of_multiples([3, 5], 4, Result),
+        Result == 3.
 
     test(a_few_multiples, condition(pending)) :-
-        sum_of_multiples([3, 5], 10, 23).
+        sum_of_multiples([3, 5], 10, Result),
+        Result == 23.
 
     test(sum_more_multiples, condition(pending)) :-
-        sum_of_multiples([3, 5], 100, 2318).
+        sum_of_multiples([3, 5], 100, Result),
+        Result == 2318.
 
     test(even_more_multiples, condition(pending)) :-
-        sum_of_multiples([3, 5], 1000, 233168).
+        sum_of_multiples([3, 5], 1000, Result),
+        Result == 233168.
 
     test(new_factors, condition(pending)) :-
-        sum_of_multiples([7, 13, 17], 20, 51).
+        sum_of_multiples([7, 13, 17], 20, Result),
+        Result == 51.
 
     test(sum_more_new_factors, condition(pending)) :-
-        sum_of_multiples([4, 6], 15, 30).
+        sum_of_multiples([4, 6], 15, Result),
+        Result == 30.
 
     test(even_more_new_factors, condition(pending)) :-
-        sum_of_multiples([5, 6, 8], 150, 4419).
+        sum_of_multiples([5, 6, 8], 150, Result),
+        Result == 4419.
 
     test(divisible_factor, condition(pending)) :-
-        sum_of_multiples([5, 25], 51, 275).
+        sum_of_multiples([5, 25], 51, Result),
+        Result == 275.
 
     test(large_factors, condition(pending)) :-
-        sum_of_multiples([43, 47], 10000, 2203160).
+        sum_of_multiples([43, 47], 10000, Result),
+        Result == 2203160.
 
     test(every_num, condition(pending)) :-
-        sum_of_multiples([1], 100, 4950).
+        sum_of_multiples([1], 100, Result),
+        Result == 4950.
 
     test(no_factors, condition(pending)) :-
-        sum_of_multiples([], 10000, 0).
+        sum_of_multiples([], 10000, Result),
+        Result == 0.
 
 :- end_tests(sum_of_multiples).