diff --git a/tools/exceptionHolidays.pl b/tools/exceptionHolidays.pl
index c820a92fff..64a4860063 100755
--- a/tools/exceptionHolidays.pl
+++ b/tools/exceptionHolidays.pl
@@ -1,6 +1,8 @@
 #!/usr/bin/perl
 
 use strict;
+use warnings;
+
 use CGI;
 
 use C4::Auth;
diff --git a/tools/holidays.pl b/tools/holidays.pl
index 93808f0e1f..5d7ab2ef64 100755
--- a/tools/holidays.pl
+++ b/tools/holidays.pl
@@ -17,6 +17,8 @@
 
 #####Sets holiday periods for each branch. Datedues will be extended if branch is closed -TG
 use strict;
+use warnings;
+
 use CGI;
 
 use C4::Auth;
diff --git a/tools/newHolidays.pl b/tools/newHolidays.pl
index 08cb7dd6fc..34469d85f9 100755
--- a/tools/newHolidays.pl
+++ b/tools/newHolidays.pl
@@ -1,6 +1,8 @@
 #!/usr/bin/perl
 
 use strict;
+use warnings;
+
 use CGI;
 
 use C4::Auth;
diff --git a/tools/tools-home.pl b/tools/tools-home.pl
index c49d2e7ba9..7028358547 100755
--- a/tools/tools-home.pl
+++ b/tools/tools-home.pl
@@ -16,6 +16,8 @@
 # Suite 330, Boston, MA  02111-1307 USA
 
 use strict;
+use warnings;
+
 use CGI;
 use C4::Auth;
 use C4::Output;