diff --git a/lib/Geo/Coder/List.pm b/lib/Geo/Coder/List.pm
index f0325c7..b52724b 100644
--- a/lib/Geo/Coder/List.pm
+++ b/lib/Geo/Coder/List.pm
@@ -407,6 +407,10 @@ sub geocode {
 			print 'Number of matches from ', ref($geocoder), ': ', scalar(@rc), "\n" if($self->{'debug'});
 			print Data::Dumper->new([\@rc])->Dump() if($self->{'debug'} >= 2);
 			if(defined($rc[0])) {	# check it's not an empty hash
+				if((!defined($rc[0]->{lat})) || (!defined($rc[0]->{lng}))) {
+					::diag(Data::Dumper->new([\@rc])->Dump());
+					Carp::croak("BUG: '$location': HASH exists but is not sensible");
+				}
 				if(wantarray) {
 					$self->_cache($location, \@rc);
 					return @rc;