diff --git a/bin/pt-duplicate-key-checker b/bin/pt-duplicate-key-checker
index 87a70ddc..761bda62 100755
--- a/bin/pt-duplicate-key-checker
+++ b/bin/pt-duplicate-key-checker
@@ -3339,7 +3339,7 @@ sub next {
 }
 
 sub _iterate_files {
-   my ( $self ) = @_; 
+   my ( $self ) = @_;
 
    if ( !$self->{fh} ) {
       my ($fh, $file) = $self->{file_itr}->();
diff --git a/bin/pt-index-usage b/bin/pt-index-usage
index b5fc68fd..cdaf0b82 100755
--- a/bin/pt-index-usage
+++ b/bin/pt-index-usage
@@ -4056,7 +4056,7 @@ sub next {
 }
 
 sub _iterate_files {
-   my ( $self ) = @_; 
+   my ( $self ) = @_;
 
    if ( !$self->{fh} ) {
       my ($fh, $file) = $self->{file_itr}->();
diff --git a/bin/pt-table-checksum b/bin/pt-table-checksum
index f87f8610..e124aa69 100755
--- a/bin/pt-table-checksum
+++ b/bin/pt-table-checksum
@@ -1510,7 +1510,7 @@ sub name {
 
 sub DESTROY {
    my ($self) = @_;
-   if ( $self->{dbh} ) {
+   if ( $self->{dbh} && ref($self->{dbh}) ) {
       PTDEBUG && _d('Disconnecting dbh', $self->{dbh}, $self->{name});
       $self->{dbh}->disconnect();
    }
@@ -4704,7 +4704,6 @@ sub next {
 
 sub _iterate_files {
    my ( $self ) = @_;
-   my $q = $self->{Quoter};
 
    if ( !$self->{fh} ) {
       my ($fh, $file) = $self->{file_itr}->();
diff --git a/bin/pt-table-sync b/bin/pt-table-sync
index e8a7dc1e..fed2018c 100755
--- a/bin/pt-table-sync
+++ b/bin/pt-table-sync
@@ -6897,7 +6897,7 @@ sub next {
 }
 
 sub _iterate_files {
-   my ( $self ) = @_; 
+   my ( $self ) = @_;
 
    if ( !$self->{fh} ) {
       my ($fh, $file) = $self->{file_itr}->();
diff --git a/lib/SchemaIterator.pm b/lib/SchemaIterator.pm
index c63c7eed..3cb320f3 100644
--- a/lib/SchemaIterator.pm
+++ b/lib/SchemaIterator.pm
@@ -232,7 +232,6 @@ sub next {
 
 sub _iterate_files {
    my ( $self ) = @_;
-   my $q = $self->{Quoter};
 
    if ( !$self->{fh} ) {
       my ($fh, $file) = $self->{file_itr}->();