diff --git a/hypopg_index.c b/hypopg_index.c
index d99b0aa..db119e1 100644
--- a/hypopg_index.c
+++ b/hypopg_index.c
@@ -44,10 +44,17 @@
 #include "catalog/pg_opclass.h"
 #include "catalog/pg_type.h"
 #include "commands/defrem.h"
+#if PG_VERSION_NUM >= 120000
+#include "nodes/makefuncs.h"
+#endif
 #include "optimizer/clauses.h"
 #include "optimizer/cost.h"
 #include "optimizer/pathnode.h"
+#if PG_VERSION_NUM < 120000
 #include "optimizer/var.h"
+#else
+#include "optimizer/optimizer.h"
+#endif
 #include "parser/parse_utilcmd.h"
 #include "parser/parser.h"
 #include "storage/bufmgr.h"
@@ -112,6 +119,7 @@ hypo_newIndex(Oid relid, char *accessMethod, int nkeycolumns, int ninccolumns,
 	hypoIndex  *volatile entry;
 	MemoryContext oldcontext;
 	HeapTuple	tuple;
+	Oid			oid;
 
 #if PG_VERSION_NUM >= 90600
 	IndexAmRoutine *amroutine;
@@ -130,13 +138,19 @@ hypo_newIndex(Oid relid, char *accessMethod, int nkeycolumns, int ninccolumns,
 						accessMethod)));
 	}
 
-	hypo_discover_am(accessMethod, HeapTupleGetOid(tuple));
+#if PG_VERSION_NUM < 120000
+	oid = HeapTupleGetOid(tuple);
+#else
+	oid = ((Form_pg_am) GETSTRUCT(tuple))->oid;
+#endif
+
+	hypo_discover_am(accessMethod, oid);
 
 	oldcontext = MemoryContextSwitchTo(HypoMemoryContext);
 
 	entry = palloc0(sizeof(hypoIndex));
 
-	entry->relam = HeapTupleGetOid(tuple);
+	entry->relam = oid;
 
 #if PG_VERSION_NUM >= 90600
 
@@ -544,10 +558,17 @@ hypo_index_store_parsetree(IndexStmt *node, const char *queryString)
 			}
 
 			/* get the opclass */
+#if PG_VERSION_NUM < 100000
 			opclass = GetIndexOpClass(attribute->opclass,
 									  atttype,
 									  node->accessMethod,
 									  entry->relam);
+#else
+			opclass = ResolveOpClass(attribute->opclass,
+									  atttype,
+									  node->accessMethod,
+									  entry->relam);
+#endif
 			entry->opclass[attn] = opclass;
 			/* setup the opfamily */
 			entry->opfamily[attn] = get_opclass_family(opclass);
@@ -606,7 +627,11 @@ hypo_index_store_parsetree(IndexStmt *node, const char *queryString)
 		{
 			AttrNumber	attno = entry->indexkeys[attn];
 
-			if (attno < 0 && attno != ObjectIdAttributeNumber)
+			if (attno < 0
+#if PG_VERSION_NUM < 120000
+					&& attno != ObjectIdAttributeNumber
+#endif
+					)
 				ereport(ERROR,
 						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
 						 errmsg("hypopg: index creation on system columns is not supported")));
@@ -696,7 +721,10 @@ hypo_index_store_parsetree(IndexStmt *node, const char *queryString)
 
 			for (i = FirstLowInvalidHeapAttributeNumber + 1; i < 0; i++)
 			{
-				if (i != ObjectIdAttributeNumber &&
+				if (
+#if PG_VERSION_NUM < 120000
+						i != ObjectIdAttributeNumber &&
+#endif
 					bms_is_member(i - FirstLowInvalidHeapAttributeNumber,
 								  indexattrs))
 					ereport(ERROR,
diff --git a/import/hypopg_import_index.c b/import/hypopg_import_index.c
index 22d84db..d482f30 100644
--- a/import/hypopg_import_index.c
+++ b/import/hypopg_import_index.c
@@ -22,6 +22,9 @@
 #include "nodes/makefuncs.h"
 #include "nodes/pg_list.h"
 #include "optimizer/clauses.h"
+#if PG_VERSION_NUM >= 120000
+#include "optimizer/optimizer.h"
+#endif
 #include "optimizer/planner.h"
 #include "optimizer/pathnode.h"
 #if PG_VERSION_NUM >= 110000
@@ -63,8 +66,11 @@ build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 			const FormData_pg_attribute *att_tup;
 
 			if (indexkey < 0)
-				att_tup = SystemAttributeDefinition(indexkey,
-										   heapRelation->rd_rel->relhasoids);
+				att_tup = SystemAttributeDefinition(indexkey
+#if PG_VERSION_NUM < 120000
+										   , heapRelation->rd_rel->relhasoids
+#endif
+										   );
 			else
 #if PG_VERSION_NUM >= 110000
 				att_tup = TupleDescAttr(heapRelation->rd_att, indexkey - 1);
@@ -100,6 +106,7 @@ build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 	return tlist;
 }
 
+#if PG_VERSION_NUM < 100000
 /*
  * Copied from src/backend/commands/indexcmds.c, not exported.
  * Resolve possibly-defaulted operator class specification
@@ -214,6 +221,7 @@ GetIndexOpClass(List *opclass, Oid attrType,
 
 	return opClassId;
 }
+#endif
 
 /*
  * Copied from src/backend/commands/indexcmds.c, not exported.
diff --git a/include/hypopg.h b/include/hypopg.h
index 6e40ceb..5fab96d 100644
--- a/include/hypopg.h
+++ b/include/hypopg.h
@@ -12,6 +12,9 @@
 #ifndef _HYPOPG_H_
 #define _HYPOPG_H_
 
+#if PG_VERSION_NUM >= 120000
+#include "access/table.h"
+#endif
 #include "catalog/catalog.h"
 #include "commands/explain.h"
 #include "nodes/nodeFuncs.h"
diff --git a/include/hypopg_import_index.h b/include/hypopg_import_index.h
index 4715771..29b5ec8 100644
--- a/include/hypopg_import_index.h
+++ b/include/hypopg_import_index.h
@@ -21,8 +21,10 @@
 
 extern List *build_index_tlist(PlannerInfo *root, IndexOptInfo *index,
 				  Relation heapRelation);
+#if PG_VERSION_NUM < 100000
 extern Oid GetIndexOpClass(List *opclass, Oid attrType,
 				char *accessMethodName, Oid accessMethodId);
+#endif
 
 extern void CheckPredicate(Expr *predicate);
 extern bool CheckMutability(Expr *expr);