diff --git a/src/neogb/data.h b/src/neogb/data.h
index fb97fd80..af5f6201 100644
--- a/src/neogb/data.h
+++ b/src/neogb/data.h
@@ -130,6 +130,7 @@ struct ht_t
     len_t ebl;    /* elimination block length:
                    * degree + #elimination variables,
                    * 0 if no elimination order */
+    int32_t mo;   /* monomial ordering: 0=DRL, 1=LEX */
     len_t nv;     /* number of variables */
     len_t evl;    /* real length of exponent vector,
                    * includes degree (or two degrees
diff --git a/src/neogb/hash.c b/src/neogb/hash.c
index eb02a947..619dd48e 100644
--- a/src/neogb/hash.c
+++ b/src/neogb/hash.c
@@ -53,6 +53,7 @@ ht_t *initialize_basis_hash_table(
 
     ht_t *ht  = (ht_t *)malloc(sizeof(ht_t));
     ht->nv    = nv;
+    ht->mo    = st->mo;
     /* generate map */
     ht->bpv = (len_t)((CHAR_BIT * sizeof(sdm_t)) / (unsigned long)nv);
     if (ht->bpv == 0) {
@@ -136,6 +137,7 @@ ht_t *copy_hash_table(
     ht_t *ht  = (ht_t *)malloc(sizeof(ht_t));
 
     ht->nv    = bht->nv;
+    ht->mo    = bht->mo;
     ht->evl   = bht->evl;
     ht->ebl   = bht->ebl;
     ht->hsz   = bht->hsz;
@@ -187,6 +189,7 @@ ht_t *initialize_secondary_hash_table(
 
     ht_t *ht  = (ht_t *)malloc(sizeof(ht_t)); 
     ht->nv    = bht->nv;
+    ht->mo    = bht->mo;
     ht->evl   = bht->evl;
     ht->ebl   = bht->ebl;