diff --git a/src/pg/test/expected/08_interpolation_test.out b/src/pg/test/expected/08_interpolation_test.out
index 42d24cb..b927f63 100644
--- a/src/pg/test/expected/08_interpolation_test.out
+++ b/src/pg/test/expected/08_interpolation_test.out
@@ -1,4 +1,2 @@
- cdb_spatialinterpolation
---------------------------
- 780.79470198683925288365
-(1 row)
+cdb_spatialinterpolation
+t
diff --git a/src/pg/test/sql/08_interpolation_test.sql b/src/pg/test/sql/08_interpolation_test.sql
index c8db89d..43e7ee9 100644
--- a/src/pg/test/sql/08_interpolation_test.sql
+++ b/src/pg/test/sql/08_interpolation_test.sql
@@ -1,6 +1,9 @@
+\pset format unaligned
+\set ECHO all
+
 WITH a AS (
     SELECT
     ARRAY[800, 700, 600, 500, 400, 300, 200, 100] AS vals,
     ARRAY[ST_GeomFromText('POINT(2.1744 41.403)'),ST_GeomFromText('POINT(2.1228 41.380)'),ST_GeomFromText('POINT(2.1511 41.374)'),ST_GeomFromText('POINT(2.1528 41.413)'),ST_GeomFromText('POINT(2.165 41.391)'),ST_GeomFromText('POINT(2.1498 41.371)'),ST_GeomFromText('POINT(2.1533 41.368)'),ST_GeomFromText('POINT(2.131386 41.41399)')] AS g
 )
-SELECT CDB_SpatialInterpolation(g, vals, ST_GeomFromText('POINT(2.154 41.37)'),1) FROM a;
+SELECT (cdb_crankshaft.CDB_SpatialInterpolation(g, vals, ST_GeomFromText('POINT(2.154 41.37)'), 1) - 780.79470198683925288365) / 780.79470198683925288365 < 0.001 FROM a;