diff --git a/src/hnsw.c b/src/hnsw.c
index e6558f7..3054d01 100644
--- a/src/hnsw.c
+++ b/src/hnsw.c
@@ -266,6 +266,7 @@ hnswvalidate(Oid opclassoid)
 	HeapTuple	classtup;
 	Form_pg_opclass classform;
 	Oid			opcintype;
+	char	   *opclassname;
 	Oid			opfamilyoid;
 #if PG_VERSION_NUM < 180000
 	HeapTuple	familytup;
@@ -274,6 +275,9 @@ hnswvalidate(Oid opclassoid)
 	char	   *opfamilyname;
 	CatCList   *proclist;
 	CatCList   *oprlist;
+	List	   *grouplist;
+	OpFamilyOpFuncGroup *opclassgroup;
+	ListCell   *lc;
 
 	/* Fetch opclass information */
 	classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
@@ -281,6 +285,7 @@ hnswvalidate(Oid opclassoid)
 		elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
 	classform = (Form_pg_opclass) GETSTRUCT(classtup);
 	opcintype = classform->opcintype;
+	opclassname = NameStr(classform->opcname);
 
 	/* Fetch opfamily information */
 	opfamilyoid = classform->opcfamily;
@@ -392,6 +397,31 @@ hnswvalidate(Oid opclassoid)
 		}
 	}
 
+	grouplist = identify_opfamily_groups(oprlist, proclist);
+	opclassgroup = NULL;
+	foreach(lc, grouplist)
+	{
+		OpFamilyOpFuncGroup *thisgroup = (OpFamilyOpFuncGroup *) lfirst(lc);
+
+		if (thisgroup->lefttype == opcintype &&
+			thisgroup->righttype == opcintype)
+			opclassgroup = thisgroup;
+	}
+
+	/* Check required support functions */
+	for (int i = 1; i <= HNSW_NPROCS; i++)
+	{
+		if (opclassgroup && (opclassgroup->functionset & (((int64) 1) << i)) != 0)
+			continue;
+		if (i == HNSW_NORM_PROC || i == HNSW_TYPE_INFO_PROC)
+			continue;
+		ereport(INFO,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("operator class \"%s\" of access method %s is missing support function %d",
+						opclassname, "hnsw", i)));
+		result = false;
+	}
+
 	ReleaseCatCacheList(proclist);
 	ReleaseCatCacheList(oprlist);
 #if PG_VERSION_NUM < 180000
@@ -415,7 +445,7 @@ hnswhandler(PG_FUNCTION_ARGS)
 	static const IndexAmRoutine amroutine = {
 		.type = T_IndexAmRoutine,
 		.amstrategies = 0,
-		.amsupport = 3,
+		.amsupport = HNSW_NPROCS,
 		.amoptsprocnum = 0,
 		.amcanorder = false,
 		.amcanorderbyop = true,
@@ -472,7 +502,7 @@ hnswhandler(PG_FUNCTION_ARGS)
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
 	amroutine->amstrategies = 0;
-	amroutine->amsupport = 3;
+	amroutine->amsupport = HNSW_NPROCS;
 	amroutine->amoptsprocnum = 0;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = true;
diff --git a/src/hnsw.h b/src/hnsw.h
index 31b9a11..c416f0f 100644
--- a/src/hnsw.h
+++ b/src/hnsw.h
@@ -37,6 +37,7 @@ typedef Pointer Item;
 #define HNSW_DISTANCE_PROC 1
 #define HNSW_NORM_PROC 2
 #define HNSW_TYPE_INFO_PROC 3
+#define HNSW_NPROCS 3
 
 #define HNSW_VERSION	1
 #define HNSW_MAGIC_NUMBER 0xA953A953
diff --git a/src/ivfflat.c b/src/ivfflat.c
index 131b091..b78a1e8 100644
--- a/src/ivfflat.c
+++ b/src/ivfflat.c
@@ -183,6 +183,7 @@ ivfflatvalidate(Oid opclassoid)
 	HeapTuple	classtup;
 	Form_pg_opclass classform;
 	Oid			opcintype;
+	char	   *opclassname;
 	Oid			opfamilyoid;
 #if PG_VERSION_NUM < 180000
 	HeapTuple	familytup;
@@ -191,6 +192,9 @@ ivfflatvalidate(Oid opclassoid)
 	char	   *opfamilyname;
 	CatCList   *proclist;
 	CatCList   *oprlist;
+	List	   *grouplist;
+	OpFamilyOpFuncGroup *opclassgroup;
+	ListCell   *lc;
 
 	/* Fetch opclass information */
 	classtup = SearchSysCache1(CLAOID, ObjectIdGetDatum(opclassoid));
@@ -198,6 +202,7 @@ ivfflatvalidate(Oid opclassoid)
 		elog(ERROR, "cache lookup failed for operator class %u", opclassoid);
 	classform = (Form_pg_opclass) GETSTRUCT(classtup);
 	opcintype = classform->opcintype;
+	opclassname = NameStr(classform->opcname);
 
 	/* Fetch opfamily information */
 	opfamilyoid = classform->opcfamily;
@@ -315,6 +320,31 @@ ivfflatvalidate(Oid opclassoid)
 		}
 	}
 
+	grouplist = identify_opfamily_groups(oprlist, proclist);
+	opclassgroup = NULL;
+	foreach(lc, grouplist)
+	{
+		OpFamilyOpFuncGroup *thisgroup = (OpFamilyOpFuncGroup *) lfirst(lc);
+
+		if (thisgroup->lefttype == opcintype &&
+			thisgroup->righttype == opcintype)
+			opclassgroup = thisgroup;
+	}
+
+	/* Check required support functions */
+	for (int i = 1; i <= IVFFLAT_NPROCS; i++)
+	{
+		if (opclassgroup && (opclassgroup->functionset & (((int64) 1) << i)) != 0)
+			continue;
+		if (i == IVFFLAT_NORM_PROC || i == IVFFLAT_KMEANS_NORM_PROC || i == IVFFLAT_TYPE_INFO_PROC)
+			continue;
+		ereport(INFO,
+				(errcode(ERRCODE_INVALID_OBJECT_DEFINITION),
+				 errmsg("operator class \"%s\" of access method %s is missing support function %d",
+						opclassname, "hnsw", i)));
+		result = false;
+	}
+
 	ReleaseCatCacheList(proclist);
 	ReleaseCatCacheList(oprlist);
 #if PG_VERSION_NUM < 180000
@@ -338,7 +368,7 @@ ivfflathandler(PG_FUNCTION_ARGS)
 	static const IndexAmRoutine amroutine = {
 		.type = T_IndexAmRoutine,
 		.amstrategies = 0,
-		.amsupport = 5,
+		.amsupport = IVFFLAT_NPROCS,
 		.amoptsprocnum = 0,
 		.amcanorder = false,
 		.amcanorderbyop = true,
@@ -395,7 +425,7 @@ ivfflathandler(PG_FUNCTION_ARGS)
 	IndexAmRoutine *amroutine = makeNode(IndexAmRoutine);
 
 	amroutine->amstrategies = 0;
-	amroutine->amsupport = 5;
+	amroutine->amsupport = IVFFLAT_NPROCS;
 	amroutine->amoptsprocnum = 0;
 	amroutine->amcanorder = false;
 	amroutine->amcanorderbyop = true;
diff --git a/src/ivfflat.h b/src/ivfflat.h
index 462017b..19ae541 100644
--- a/src/ivfflat.h
+++ b/src/ivfflat.h
@@ -39,6 +39,7 @@ typedef Pointer Item;
 #define IVFFLAT_KMEANS_DISTANCE_PROC 3
 #define IVFFLAT_KMEANS_NORM_PROC 4
 #define IVFFLAT_TYPE_INFO_PROC 5
+#define IVFFLAT_NPROCS 5
 
 #define IVFFLAT_VERSION	1
 #define IVFFLAT_MAGIC_NUMBER 0x14FF1A7