diff --git a/Build.PL b/Build.PL
index f501f2f311..bdf9f69556 100644
--- a/Build.PL
+++ b/Build.PL
@@ -1,3 +1,6 @@
+use warnings;
+use strict;
+
 use lib 'inc';
 use Local::Module::Build;
 
diff --git a/lib/NGCP/Panel/Block/Block.pm b/lib/NGCP/Panel/Block/Block.pm
index 7f667e1ab3..a52c5da509 100644
--- a/lib/NGCP/Panel/Block/Block.pm
+++ b/lib/NGCP/Panel/Block/Block.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Block::Block;
 
+use warnings;
+use strict;
+
 use Template;
 
 sub new {
diff --git a/lib/NGCP/Panel/Block/Contract/ProfileMappingsList.pm b/lib/NGCP/Panel/Block/Contract/ProfileMappingsList.pm
index 14bbb2ee46..bb22ddc788 100644
--- a/lib/NGCP/Panel/Block/Contract/ProfileMappingsList.pm
+++ b/lib/NGCP/Panel/Block/Contract/ProfileMappingsList.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Block::Contract::ProfileMappingsList;
 
+use warnings;
+use strict;
+
 use parent ("NGCP::Panel::Block::Block");
 
 sub template {
diff --git a/lib/NGCP/Panel/Block/Contract/ProfileMappingsTimeline.pm b/lib/NGCP/Panel/Block/Contract/ProfileMappingsTimeline.pm
index 216df332a8..abb51a488c 100644
--- a/lib/NGCP/Panel/Block/Contract/ProfileMappingsTimeline.pm
+++ b/lib/NGCP/Panel/Block/Contract/ProfileMappingsTimeline.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Block::Contract::ProfileMappingsTimeline;
 
+use warnings;
+use strict;
+
 use parent ("NGCP::Panel::Block::Block");
 
 sub template {
diff --git a/lib/NGCP/Panel/Block/Contract/ProfileNetworkMappings.pm b/lib/NGCP/Panel/Block/Contract/ProfileNetworkMappings.pm
index 757d7437cb..49da15d29f 100644
--- a/lib/NGCP/Panel/Block/Contract/ProfileNetworkMappings.pm
+++ b/lib/NGCP/Panel/Block/Contract/ProfileNetworkMappings.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Block::Contract::ProfileNetworkMappings;
 
+use warnings;
+use strict;
+
 use parent ("NGCP::Panel::Block::Block");
 
 sub template {
diff --git a/lib/NGCP/Panel/Controller/API/MetaConfigDefs.pm b/lib/NGCP/Panel/Controller/API/MetaConfigDefs.pm
index bbdcc7f6db..1a9410ea14 100644
--- a/lib/NGCP/Panel/Controller/API/MetaConfigDefs.pm
+++ b/lib/NGCP/Panel/Controller/API/MetaConfigDefs.pm
@@ -1,4 +1,8 @@
 package NGCP::Panel::Controller::API::MetaConfigDefs;
+
+use warnings;
+use strict;
+
 use NGCP::Panel::Utils::Generic qw(:all);
 use boolean qw(true);
 use Data::HAL qw();
diff --git a/lib/NGCP/Panel/Form.pm b/lib/NGCP/Panel/Form.pm
index 489184aff8..89a1a926f8 100644
--- a/lib/NGCP/Panel/Form.pm
+++ b/lib/NGCP/Panel/Form.pm
@@ -1,4 +1,8 @@
 package NGCP::Panel::Form;
+
+use warnings;
+use strict;
+
 use Module::Load::Conditional qw/can_load/;
 
 my %forms = ();
diff --git a/lib/NGCP/Panel/Template/Plugin/DeviceConfig.pm b/lib/NGCP/Panel/Template/Plugin/DeviceConfig.pm
index c68f1f12ef..b7e4befe65 100644
--- a/lib/NGCP/Panel/Template/Plugin/DeviceConfig.pm
+++ b/lib/NGCP/Panel/Template/Plugin/DeviceConfig.pm
@@ -1,4 +1,8 @@
 package NGCP::Panel::Template::Plugin::DeviceConfig;
+
+use warnings;
+use strict;
+
 use parent 'Template::Plugin';
 use Crypt::RC4;
 
diff --git a/lib/NGCP/Panel/Utils/DeviceFirmware.pm b/lib/NGCP/Panel/Utils/DeviceFirmware.pm
index 1884ae53bb..2a81341fdc 100644
--- a/lib/NGCP/Panel/Utils/DeviceFirmware.pm
+++ b/lib/NGCP/Panel/Utils/DeviceFirmware.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Utils::DeviceFirmware;
 
+use warnings;
+use strict;
+
 use English;
 
 sub insert_firmware_data {
diff --git a/lib/NGCP/Panel/Utils/Fax.pm b/lib/NGCP/Panel/Utils/Fax.pm
index 69fc9403a4..3b7dc6d7f9 100644
--- a/lib/NGCP/Panel/Utils/Fax.pm
+++ b/lib/NGCP/Panel/Utils/Fax.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Utils::Fax;
 
+use warnings;
+use strict;
+
 use English;
 use File::Temp qw/tempfile/;
 use File::Slurp;
@@ -76,7 +79,7 @@ sub send_fax {
     my $client = new NGCP::Fax;
     use Data::Dumper;
     $c->log->debug('invoke send_fax with args: ' . Dumper(\%sendfax_args));
-    $client->send_fax(\%sendfax_args);
+    my $res = $client->send_fax(\%sendfax_args);
     $c->log->debug("webfax: res=$res;");
 }
 
@@ -120,9 +123,10 @@ sub get_fax {
         return unless $filepath;
     } else {
         if ($format) {
-            ($tmp_fh, $filepath) =
-                File::Temp::tempfile( DIR => $cfg->{spool_dir}."/tmp")
-                    or $self->error("Cannot create temp file: $ERRNO");
+            unless ( ($tmp_fh, $filepath) = File::Temp::tempfile( DIR => $c->config->{faxserver}{spool_dir}."/tmp") ) {
+                $c->log->error("Cannot create temp file: $ERRNO");
+                return;
+            }
             binmode $tmp_fh;
             close $tmp_fh;
             print $tmp_fh $item->voip_fax_data->data;
@@ -167,7 +171,7 @@ sub process_fax_journal_item {
     my $dst_sub  = $result->callee_subscriber // undef; #undef, if not local, or if callee is username
     #try finding it:
     unless ($dst_sub) {
-        my $dst_src_sub = $c->model('DB')->resultset('provisioning_voip_subscribers')->search({
+        my $prov_dst_sub = $c->model('DB')->resultset('provisioning_voip_subscribers')->search({
             'username' => $result->callee,
         })->first();
         if ($prov_dst_sub) {
diff --git a/lib/NGCP/Panel/Utils/Interception.pm b/lib/NGCP/Panel/Utils/Interception.pm
index cf34a1d102..6d2f8dcf75 100644
--- a/lib/NGCP/Panel/Utils/Interception.pm
+++ b/lib/NGCP/Panel/Utils/Interception.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Utils::Interception;
 
+use warnings;
+use strict;
+
 use Data::Dumper;
 use LWP::UserAgent;
 use TryCatch;
diff --git a/lib/NGCP/Panel/Utils/MySQL.pm b/lib/NGCP/Panel/Utils/MySQL.pm
index 0990ac18dc..0cd19b3979 100644
--- a/lib/NGCP/Panel/Utils/MySQL.pm
+++ b/lib/NGCP/Panel/Utils/MySQL.pm
@@ -1,5 +1,8 @@
 package NGCP::Panel::Utils::MySQL;
 
+use warnings;
+use strict;
+
 sub bulk_insert {
 	my(%params) = @_;
 	my ($c, $s, $trans, $query, $data, $chunksize) = @params{qw/c schema do_transaction query data chunk_size/};
diff --git a/sandbox/create_lnp_csv.pl b/sandbox/create_lnp_csv.pl
index ea5d6d7182..592c7ea20d 100755
--- a/sandbox/create_lnp_csv.pl
+++ b/sandbox/create_lnp_csv.pl
@@ -1,5 +1,8 @@
 #!/usr/bin/perl -w
 
+use warnings;
+use strict;
+
 my $path = '/tmp/lnp.csv';
 
 my $carrier_base = 'carrier_';
diff --git a/sandbox/inheritance.pl b/sandbox/inheritance.pl
index 27e537d242..8131fe4679 100644
--- a/sandbox/inheritance.pl
+++ b/sandbox/inheritance.pl
@@ -1,5 +1,8 @@
 package Parent;
 
+use warnings;
+use strict;
+
 our $VERSION = 1.23;
 
 sub VERSION { $VERSION }
diff --git a/sandbox/tracemem.pm b/sandbox/tracemem.pm
index 828622fff3..cf7c7edacd 100644
--- a/sandbox/tracemem.pm
+++ b/sandbox/tracemem.pm
@@ -1,3 +1,5 @@
+
+## no critic (RequireUseWarnings, RequireUseStrict)
 our $old = 0;
 BEGIN {
     unshift @INC, sub {
diff --git a/script/ngcp_panel_cgi.pl b/script/ngcp_panel_cgi.pl
index 052db7d1cd..0553913534 100755
--- a/script/ngcp_panel_cgi.pl
+++ b/script/ngcp_panel_cgi.pl
@@ -1,5 +1,8 @@
 #!/usr/bin/env perl
 
+use warnings;
+use strict;
+
 use Catalyst::ScriptRunner;
 Catalyst::ScriptRunner->run('NGCP::Panel', 'CGI');
 
diff --git a/script/ngcp_panel_decode_crash b/script/ngcp_panel_decode_crash
index eac307bddc..b0d46b2aba 100755
--- a/script/ngcp_panel_decode_crash
+++ b/script/ngcp_panel_decode_crash
@@ -1,4 +1,8 @@
 #!/usr/bin/env perl
+
+use warnings;
+use strict;
+
 use Convert::Ascii85 qw();
 use IO::Uncompress::UnXz qw(unxz $UnXzError);
 
diff --git a/script/ngcp_panel_fastcgi.pl b/script/ngcp_panel_fastcgi.pl
index a4dea79158..0519762800 100755
--- a/script/ngcp_panel_fastcgi.pl
+++ b/script/ngcp_panel_fastcgi.pl
@@ -1,5 +1,8 @@
 #!/usr/bin/env perl
 
+use warnings;
+use strict;
+
 use Catalyst::ScriptRunner;
 Catalyst::ScriptRunner->run('NGCP::Panel', 'FastCGI');
 
diff --git a/script/ngcp_panel_server.pl b/script/ngcp_panel_server.pl
index 7b700770c4..d90ec49e58 100755
--- a/script/ngcp_panel_server.pl
+++ b/script/ngcp_panel_server.pl
@@ -1,5 +1,8 @@
 #!/usr/bin/env perl
 
+use warnings;
+use strict;
+
 BEGIN {
     $ENV{CATALYST_SCRIPT_GEN} = 40;
 }
diff --git a/script/ngcp_panel_test.pl b/script/ngcp_panel_test.pl
index 38fe843fa5..30f4cd4f6c 100755
--- a/script/ngcp_panel_test.pl
+++ b/script/ngcp_panel_test.pl
@@ -1,5 +1,8 @@
 #!/usr/bin/env perl
 
+use warnings;
+use strict;
+
 use Catalyst::ScriptRunner;
 Catalyst::ScriptRunner->run('NGCP::Panel', 'Test');
 
diff --git a/t/api-rest/api-customerfraudpreferences.t b/t/api-rest/api-customerfraudpreferences.t
index f428278376..cfaaf1595a 100644
--- a/t/api-rest/api-customerfraudpreferences.t
+++ b/t/api-rest/api-customerfraudpreferences.t
@@ -1,3 +1,6 @@
+use warnings;
+use strict;
+
 #use Sipwise::Base;
 use Net::Domain qw(hostfqdn);
 use JSON qw();
diff --git a/t/api-rest/api-threads.t b/t/api-rest/api-threads.t
index 8855a1f3c8..b4b7cf77ca 100644
--- a/t/api-rest/api-threads.t
+++ b/t/api-rest/api-threads.t
@@ -1,7 +1,9 @@
+use warnings;
+use strict;
+
 use threads qw();
-#use Sipwise::Base;
-use Test::More;
 
+use Test::More;
 
 
 BEGIN {