diff --git a/m-algo.h b/m-algo.h
index 137676f5..7b93ce1e 100644
--- a/m-algo.h
+++ b/m-algo.h
@@ -935,6 +935,7 @@
 #define ALGOI_REDUCE_AND(a,b) ((a) &= (b))
 #define ALGOI_REDUCE_OR(a,b)  ((a) |= (b))
 #define ALGOI_REDUCE_SUM(a,b) ((a) += (b))
+#define ALGOI_REDUCE_PRODUCT(a,b) ((a) *= (b))
 
 /* Return the method associated to a reduce operation.
    It returns the special function handler if function is and, or, sum or add.
@@ -945,7 +946,11 @@
    M_IF(M_KEYWORD_P(or, reduceFunc))             \
    (ALGOI_REDUCE_OR,                             \
     M_IF(M_KEYWORD_P(sum, reduceFunc))           \
-    (ALGOI_REDUCE_SUM, reduceFunc)               \
+    (ALGOI_REDUCE_SUM,                           \
+     M_IF(M_KEYWORD_P(product, reduceFunc))      \
+     (ALGOI_REDUCE_PRODUCT,                      \
+      reduceFunc)                                \
+     )                                           \
     )                                            \
    )
 
diff --git a/m-core.h b/m-core.h
index 70519401..302bc90a 100644
--- a/m-core.h
+++ b/m-core.h
@@ -817,6 +817,8 @@ extern void m_no_default_function(void)   __attribute__((error("The requested op
 #define M_PATTERN_sum_add ,
 #define M_PATTERN_add_add ,
 #define M_PATTERN_add_sum ,
+#define M_PATTERN_product_product ,
+#define M_PATTERN_product_mul ,
 #define M_PATTERN_bool_bool ,
 
 
diff --git a/tests/test-malgo.c b/tests/test-malgo.c
index 09ce1aa8..cdf0ca4d 100644
--- a/tests/test-malgo.c
+++ b/tests/test-malgo.c
@@ -502,6 +502,8 @@ static void test_extract(void)
   assert (dst == 0);
   ALGO_REDUCE(dst, a, ARRAY_OPLIST(array_int), or);
   assert (dst == 127);
+  ALGO_REDUCE(dst, a, ARRAY_OPLIST(array_int), product);
+  assert (dst == 0);
 
   array_int_clear(a);
   list_int_clear(l);