diff --git a/modules/Bio/EnsEMBL/Exon.pm b/modules/Bio/EnsEMBL/Exon.pm
index 868c0cd8bd118abf08d9e780bd31a18d7bee829a..425a1d683e932340e2e119491f71593441719183 100755
--- a/modules/Bio/EnsEMBL/Exon.pm
+++ b/modules/Bio/EnsEMBL/Exon.pm
@@ -849,6 +849,7 @@ sub equals {
   my ( $self, $exon ) = @_;
 
   if ( $self eq $exon ) { return 1 }
+  if ( ! defined $exon ) { return 0 }
 
   assert_ref( $exon, 'Bio::EnsEMBL::Exon' );
 
diff --git a/modules/Bio/EnsEMBL/Gene.pm b/modules/Bio/EnsEMBL/Gene.pm
index 22bbd0b0ceec3bf424913995d9b11a0fda4e1025..3fcfd9472333d1fa831dfdee9295c5f5b9d9a65a 100755
--- a/modules/Bio/EnsEMBL/Gene.pm
+++ b/modules/Bio/EnsEMBL/Gene.pm
@@ -390,6 +390,7 @@ sub equals {
   my ( $self, $gene ) = @_;
 
   if ( $self eq $gene ) { return 1 }
+  if ( ! defined $gene ) { return 0 }
 
   assert_ref( $gene, 'Bio::EnsEMBL::Gene' );