diff --git a/src/backend/catalog/dependency.c b/src/backend/catalog/dependency.c
index de10923391..f10abd78b7 100644
--- a/src/backend/catalog/dependency.c
+++ b/src/backend/catalog/dependency.c
@@ -1840,6 +1840,13 @@ find_expr_references_walker(Node *node,
 						add_object_address(OCLASS_TYPE, objoid, 0,
 										   context->addrs);
 					break;
+				case REGCOLLATIONOID:
+					objoid = DatumGetObjectId(con->constvalue);
+					if (SearchSysCacheExists1(COLLOID,
+											  ObjectIdGetDatum(objoid)))
+						add_object_address(OCLASS_COLLATION, objoid, 0,
+										   context->addrs);
+					break;
 				case REGCONFIGOID:
 					objoid = DatumGetObjectId(con->constvalue);
 					if (SearchSysCacheExists1(TSCONFIGOID,
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index fa1f589fad..1884918318 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -4326,6 +4326,7 @@ convert_to_scalar(Datum value, Oid valuetypid, Oid collid, double *scaledvalue,
 		case REGOPERATOROID:
 		case REGCLASSOID:
 		case REGTYPEOID:
+		case REGCOLLATIONOID:
 		case REGCONFIGOID:
 		case REGDICTIONARYOID:
 		case REGROLEOID:
@@ -4457,6 +4458,7 @@ convert_numeric_to_scalar(Datum value, Oid typid, bool *failure)
 		case REGOPERATOROID:
 		case REGCLASSOID:
 		case REGTYPEOID:
+		case REGCOLLATIONOID:
 		case REGCONFIGOID:
 		case REGDICTIONARYOID:
 		case REGROLEOID:
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index 6ae7c1f50b..38e943fab2 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -240,6 +240,7 @@ GetCCHashEqFuncs(Oid keytype, CCHashFN *hashfunc, RegProcedure *eqfunc, CCFastEq
 		case REGOPERATOROID:
 		case REGCLASSOID:
 		case REGTYPEOID:
+		case REGCOLLATIONOID:
 		case REGCONFIGOID:
 		case REGDICTIONARYOID:
 		case REGROLEOID: