diff --git a/test/geocoder_test.rb b/test/geocoder_test.rb
index c5b1efdf08cd5e88938021d7f6fd3db06427596c..4c62ec1f3a28b9c35178da7fcb9104f8dada5c2a 100644
--- a/test/geocoder_test.rb
+++ b/test/geocoder_test.rb
@@ -208,13 +208,14 @@ class GeocoderTest < Test::Unit::TestCase
   private # ------------------------------------------------------------------
 
   def assert_result_has_required_attributes(result)
-    assert result.coordinates.is_a?(Array)
-    assert result.latitude.is_a?(Float)
-    assert result.longitude.is_a?(Float)
-    assert result.city.is_a?(String)
-    assert result.postal_code.is_a?(String)
-    assert result.country.is_a?(String)
-    assert result.country_code.is_a?(String)
-    assert_not_nil result.address
+    m = "Lookup #{Geocoder::Configuration.lookup} does not support %s attribute."
+    assert result.coordinates.is_a?(Array),   m % "coordinates"
+    assert result.latitude.is_a?(Float),      m % "latitude"
+    assert result.longitude.is_a?(Float),     m % "longitude"
+    assert result.city.is_a?(String),         m % "city"
+    assert result.postal_code.is_a?(String),  m % "postal_code"
+    assert result.country.is_a?(String),      m % "country"
+    assert result.country_code.is_a?(String), m % "country_code"
+    assert_not_nil result.address,            m % "address"
   end
 end