diff --git a/hypopg.c b/hypopg.c
index 4ab76b7..fe8be62 100644
--- a/hypopg.c
+++ b/hypopg.c
@@ -140,22 +140,22 @@ hypo_getNewOid(Oid relid)
 	char		relpersistence;
 
 	/* Open the relation on which we want a new OID */
-	relation = heap_open(relid, AccessShareLock);
+	relation = table_open(relid, AccessShareLock);
 
 	reltablespace = relation->rd_rel->reltablespace;
 	relpersistence = relation->rd_rel->relpersistence;
 
 	/* Close the relation and release the lock now */
-	heap_close(relation, AccessShareLock);
+	table_close(relation, AccessShareLock);
 
 	/* Open pg_class to aks a new OID */
-	pg_class = heap_open(RelationRelationId, RowExclusiveLock);
+	pg_class = table_open(RelationRelationId, RowExclusiveLock);
 
 	/* ask for a new relfilenode */
 	newoid = GetNewRelFileNode(reltablespace, pg_class, relpersistence);
 
 	/* Close pg_class and release the lock now */
-	heap_close(pg_class, RowExclusiveLock);
+	table_close(pg_class, RowExclusiveLock);
 
 	return newoid;
 }
@@ -297,7 +297,7 @@ hypo_get_relation_info_hook(PlannerInfo *root,
 		Relation	relation;
 
 		/* Open the current relation */
-		relation = heap_open(relationObjectId, AccessShareLock);
+		relation = table_open(relationObjectId, AccessShareLock);
 
 		if (relation->rd_rel->relkind == RELKIND_RELATION
 #if PG_VERSION_NUM >= 90300
@@ -324,7 +324,7 @@ hypo_get_relation_info_hook(PlannerInfo *root,
 		}
 
 		/* Close the relation release the lock now */
-		heap_close(relation, AccessShareLock);
+		table_close(relation, AccessShareLock);
 	}
 
 	if (prev_get_relation_info_hook)
diff --git a/hypopg_index.c b/hypopg_index.c
index db119e1..7a1d18a 100644
--- a/hypopg_index.c
+++ b/hypopg_index.c
@@ -1396,7 +1396,7 @@ hypopg_get_indexdef(PG_FUNCTION_ARGS)
 			if (indexpr_item == NULL)
 				elog(ERROR, "too few entries in indexprs list");
 			indexkey = (Node *) lfirst(indexpr_item);
-			indexpr_item = lnext(indexpr_item);
+			indexpr_item = lnext(entry->indexprs, indexpr_item);
 
 			/* Deparse */
 			str = deparse_expression(indexkey, context, false, false);
@@ -1546,7 +1546,7 @@ hypo_estimate_index_simple(hypoIndex * entry, BlockNumber *pages, double *tuples
 	rel = makeNode(RelOptInfo);
 
 	/* Open the hypo index' relation */
-	relation = heap_open(entry->relid, AccessShareLock);
+	relation = table_open(entry->relid, AccessShareLock);
 
 	if (!RelationNeedsWAL(relation) && RecoveryInProgress())
 		ereport(ERROR,
@@ -1567,7 +1567,7 @@ hypo_estimate_index_simple(hypoIndex * entry, BlockNumber *pages, double *tuples
 					  &rel->pages, &rel->tuples, &rel->allvisfrac);
 
 	/* Close the relation and release the lock now */
-	heap_close(relation, AccessShareLock);
+	table_close(relation, AccessShareLock);
 
 	hypo_estimate_index(entry, rel);
 	*pages = entry->pages;
diff --git a/import/hypopg_import_index.c b/import/hypopg_import_index.c
index d482f30..e6b6a2c 100644
--- a/import/hypopg_import_index.c
+++ b/import/hypopg_import_index.c
@@ -91,7 +91,7 @@ build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 			if (indexpr_item == NULL)
 				elog(ERROR, "wrong number of index expressions");
 			indexvar = (Expr *) lfirst(indexpr_item);
-			indexpr_item = lnext(indexpr_item);
+			indexpr_item = lnext(index->indexprs, indexpr_item);
 		}
 
 		tlist = lappend(tlist,
diff --git a/include/hypopg.h b/include/hypopg.h
index 5fab96d..9043264 100644
--- a/include/hypopg.h
+++ b/include/hypopg.h
@@ -22,6 +22,24 @@
 
 #include "include/hypopg_import.h"
 
+/* Provide backward compatibility macros for table.c API on pre v12 versions */
+#if PG_VERSION_NUM < 120000
+#define table_open(r, l)	heap_open(r, l)
+#define table_close(r, l)	heap_close(r, l)
+#endif
+
+/*
+ * Hacky macro to provide backward compatibility with either 1 or 2 arg lnext()
+ * on pre v13 versions
+ */
+#if PG_VERSION_NUM < 130000
+#define LNEXT(_1, _2, NAME, ...)	NAME
+#undef lnext
+#define lnext(...)			LNEXT(__VA_ARGS__, LNEXT2, LNEXT1) (__VA_ARGS__)
+#define LNEXT1(lc)			((lc)->next)
+#define LNEXT2(list, lc)	((lc)->next)
+#endif
+
 extern bool isExplain;
 
 /* GUC for enabling / disabling hypopg during EXPLAIN */