diff --git a/src/backend/catalog/genbki.pl b/src/backend/catalog/genbki.pl
index f6be50a..8d47109 100644
--- a/src/backend/catalog/genbki.pl
+++ b/src/backend/catalog/genbki.pl
@@ -343,34 +343,21 @@ EOM
 			#
 			# If the column type is oidvector or oid[], we have to replace
 			# each element of the array as per the lookup rule.
-			#
-			# If we don't have a unique value to substitute, warn and
-			# leave the entry unchanged.
 			if ($column->{lookup})
 			{
 				my $lookup = $lookup_kind{ $column->{lookup} };
+				my @lookupnames;
+				my @lookupoids;
 
 				die "unrecognized BKI_LOOKUP type " . $column->{lookup}
 				  if !defined($lookup);
 
 				if ($atttype eq 'oidvector')
 				{
-					my @lookupnames = split /\s+/, $bki_values{$attname};
-					my @lookupoids;
-					foreach my $lookupname (@lookupnames)
-					{
-						my $lookupoid = $lookup->{ $lookupname };
-						if (defined($lookupoid) && $lookupoid ne 'MULTIPLE')
-						{
-							$lookupname = $lookupoid;
-						}
-						else
-						{
-							warn "unresolved OID reference \"$lookupname\" in $catname row " . join(',', values(%bki_values))
-								if $lookupname ne '-' && $lookupname ne '0';
-						}
-						push @lookupoids, $lookupname;
-					}
+					@lookupnames = split /\s+/, $bki_values{$attname};
+					@lookupoids = lookup_oids($lookup, $catname,
+												\%bki_values, @lookupnames);
+
 					$bki_values{$attname} = join(' ', @lookupoids);
 				}
 				elsif ($atttype eq 'oid[]')
@@ -378,39 +365,21 @@ EOM
 					if ($bki_values{$attname} ne '_null_')
 					{
 						$bki_values{$attname} =~ s/[{}]//g;
-						my @lookupnames = split /,/, $bki_values{$attname};
-						my @lookupoids;
-						foreach my $lookupname (@lookupnames)
-						{
-							my $lookupoid = $lookup->{ $lookupname };
-							if (defined($lookupoid) && $lookupoid ne 'MULTIPLE')
-							{
-								$lookupname = $lookupoid;
-							}
-							else
-							{
-								warn "unresolved OID reference \"$lookupname\" in $catname row " . join(',', values(%bki_values))
-									if $lookupname ne '-' && $lookupname ne '0';
-							}
-							push @lookupoids, $lookupname;
-						}
+						@lookupnames = split /,/, $bki_values{$attname};
+						@lookupoids = lookup_oids($lookup, $catname,
+													\%bki_values, @lookupnames);
+
 						$bki_values{$attname} =
 							sprintf "{%s}", join(',', @lookupoids);
 					}
 				}
 				else
 				{
-					my $lookupname = $bki_values{$attname};
-					my $lookupoid = $lookup->{ $lookupname };
-					if (defined($lookupoid) && $lookupoid ne 'MULTIPLE')
-					{
-						$bki_values{$attname} = $lookupoid;
-					}
-					else
-					{
-						warn "unresolved OID reference \"$lookupname\" in $catname row " . join(',', values(%bki_values))
-							if $lookupname ne '-' && $lookupname ne '0';
-					}
+					$lookupnames[0] = $bki_values{$attname};
+					@lookupoids = lookup_oids($lookup, $catname,
+												\%bki_values, @lookupnames);
+
+					$bki_values{$attname} = $lookupoids[0];
 				}
 			}
 		}
@@ -759,6 +728,32 @@ sub morph_row_for_schemapg
 	}
 }
 
+# Perform OID lookups on an array of OID names.
+# If we don't have a unique value to substitute, warn and
+# leave the entry unchanged.
+sub lookup_oids
+{
+	my ($lookup, $catname, $bki_values, @lookupnames) = @_;
+
+	my @lookupoids;
+	foreach my $lookupname (@lookupnames)
+	{
+		my $lookupoid = $lookup->{$lookupname};
+		if (defined($lookupoid) and $lookupoid ne 'MULTIPLE')
+		{
+			push @lookupoids, $lookupoid;
+		}
+		else
+		{
+			push @lookupoids, $lookupname;
+			warn "unresolved OID reference \"$lookupname\" in $catname row "
+				. join(',', values(%$bki_values))
+				if $lookupname ne '-' && $lookupname ne '0';
+		}
+	}
+	return @lookupoids;
+}
+
 # Determine canonical pg_type OID #define symbol from the type name.
 sub form_pg_type_symbol
 {