diff --git a/t/01logon.t b/t/01logon.t
index deda93f..42b5011 100644
--- a/t/01logon.t
+++ b/t/01logon.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 5 }
 use DBI;
diff --git a/t/03insert.t b/t/03insert.t
index c10d791..160d1a8 100644
--- a/t/03insert.t
+++ b/t/03insert.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 use DBI;
 BEGIN { plan tests => 11 }
diff --git a/t/04select.t b/t/04select.t
index ebc1f93..a7427bc 100644
--- a/t/04select.t
+++ b/t/04select.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 21 }
 use DBI;
diff --git a/t/05tran.t b/t/05tran.t
index d297e06..27f717f 100644
--- a/t/05tran.t
+++ b/t/05tran.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 2 }
 use DBI;
diff --git a/t/06error.t b/t/06error.t
index 8269394..b188cc6 100644
--- a/t/06error.t
+++ b/t/06error.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 2 }
 use DBI;
diff --git a/t/07busy.t b/t/07busy.t
index 68d06cd..2a23f41 100644
--- a/t/07busy.t
+++ b/t/07busy.t
@@ -1,5 +1,6 @@
 #!perl
 
+use strict;
 use Test;
 BEGIN { plan tests => 8 }
 use DBI;
diff --git a/t/10dsnlist.t b/t/10dsnlist.t
index ef28d2c..36ffe0e 100644
--- a/t/10dsnlist.t
+++ b/t/10dsnlist.t
@@ -6,13 +6,15 @@
 #   after listdsn.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
 
 #
 #   Include lib.pl
 #
 require DBI;
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -39,18 +41,18 @@ sub ServerError() {
 #
 #   Main loop; leave this untouched, put tests into the loop
 #
+my @dsn;
 while (Testing()) {
     # Check if the server is awake.
-    $dbh = undef;
+    my $dbh = undef;
     Test($state or ($dbh = DBI->connect($test_dsn, $test_user,
 					$test_password)))
 	or ServerError();
 
     Test($state or (@dsn = DBI->data_sources($mdriver)) >= 0);
     if (!$state) {
-	my $d;
 	print "List of $mdriver data sources:\n";
-	foreach $d (@dsn) {
+	foreach my $d (@dsn) {
 	    print "    $d\n";
 	}
 	print "List ends.\n";
@@ -67,8 +69,7 @@ while (Testing()) {
 		    "DBI:$mdriver:test;localhost",
 		    "DBI:$mdriver:database=test;host=localhost");
     }
-    my($dsn);
-    foreach $dsn (@dsnList) {
+    foreach my $dsn (@dsnList) {
 	Test($state or ($dbh = DBI->connect($dsn, $test_user,
 					    $test_password)))
 	    or print "Cannot connect to DSN $dsn: ${DBI::errstr}\n";
diff --git a/t/12create_collation.t b/t/12create_collation.t
index 2f9aea1..f343e6a 100644
--- a/t/12create_collation.t
+++ b/t/12create_collation.t
@@ -6,6 +6,7 @@ BEGIN {
     }
 }
 
+use strict;
 use Test::More tests => 8;
 use DBI;
 use Encode qw/decode/;
@@ -27,7 +28,7 @@ my @words = qw/berger Berg
                fétu fête fève ferme/;
 
 # my @words_utf8 = map {decode("iso-8859-1", $_)} @words;
-@words_utf8 = @words;
+my @words_utf8 = @words;
 utf8::upgrade($_) foreach @words_utf8;
 
 
diff --git a/t/13progress_handler.t b/t/13progress_handler.t
index 0caa7b8..ff46feb 100644
--- a/t/13progress_handler.t
+++ b/t/13progress_handler.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 3; }
 use DBI;
diff --git a/t/30insertfetch.t b/t/30insertfetch.t
index 3674f2f..160577b 100644
--- a/t/30insertfetch.t
+++ b/t/30insertfetch.t
@@ -4,6 +4,9 @@
 #
 #   This is a simple insert/fetch test.
 #
+
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
 $^W = 1;
 
 #
@@ -19,7 +22,7 @@ $test_password = '';
 #
 use DBI;
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -42,6 +45,7 @@ sub ServerError() {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $def, $table, $cursor);
 while (Testing()) {
 
     #
diff --git a/t/40bindparam.t b/t/40bindparam.t
index 4c144a9..8ff7553 100644
--- a/t/40bindparam.t
+++ b/t/40bindparam.t
@@ -6,6 +6,8 @@
 #   and modify/extend it.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
 $^W = 1;
 
 #
@@ -22,7 +24,7 @@ $test_password = '';
 require DBI;
 use vars qw($COL_NULLABLE);
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -57,6 +59,7 @@ if (!defined(&SQL_INTEGER)) {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $def, $table, $cursor, $id, $name, $ref);
 while (Testing()) {
     #
     #   Connect to the database
diff --git a/t/40blobs.t b/t/40blobs.t
index 738d6ac..98b614d 100644
--- a/t/40blobs.t
+++ b/t/40blobs.t
@@ -6,6 +6,8 @@
 #   is expected to work correctly.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $dbdriver $state);
 $^W = 1;
 
 
@@ -24,7 +26,7 @@ $test_password = '';
 use DBI qw(:sql_types);
 
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -74,6 +76,7 @@ sub ShowBlob($) {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $table, $cursor, $row);
 while (Testing()) {
     #
     #   Connect to the database
@@ -90,7 +93,7 @@ while (Testing()) {
 	   or DbiError($dbh->error, $dbh->errstr);
 
     my($def);
-    foreach $size (128) {
+    foreach my $size (128) {
 	#
 	#   Create a new table
 	#
@@ -110,10 +113,10 @@ while (Testing()) {
 	my ($blob, $qblob) = "";
 	if (!$state) {
 	    my $b = "";
-	    for ($j = 0;  $j < 256;  $j++) {
+	    for (my $j = 0;  $j < 256;  $j++) {
 		$b .= chr($j);
 	    }
-	    for ($i = 0;  $i < $size;  $i++) {
+	    for (my $i = 0;  $i < $size;  $i++) {
 		$blob .= $b;
 	    }
 	    if ($mdriver eq 'pNET') {
diff --git a/t/40blobtext.t b/t/40blobtext.t
index 2cb1e3d..c398ec7 100644
--- a/t/40blobtext.t
+++ b/t/40blobtext.t
@@ -1,5 +1,6 @@
 #!/usr/bin/perl -w
 
+use strict;
 use Test;
 BEGIN { plan tests => 26 }
 use DBI;
diff --git a/t/40listfields.t b/t/40listfields.t
index cb523fb..353a4aa 100644
--- a/t/40listfields.t
+++ b/t/40listfields.t
@@ -5,6 +5,8 @@
 #   This is a test for statement attributes being present appropriately.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $dbdriver $state $COL_KEY $COL_NULLABLE);
 
 #
 #   Make -w happy
@@ -22,7 +24,7 @@ use DBI;
 use vars qw($verbose);
 
 $dbdriver = "";
-foreach $file ("lib.pl", "t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -32,7 +34,7 @@ foreach $file ("lib.pl", "t/lib.pl") {
 }
 
 
-@table_def = (
+my @table_def = (
 	      ["id",   "INTEGER",  4, $COL_KEY],
 	      ["name", "CHAR",    64, $COL_NULLABLE]
 	     );
@@ -51,6 +53,7 @@ sub ServerError() {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $table, $def, $cursor, $ref);
 while (Testing()) {
     #
     #   Connect to the database
@@ -90,7 +93,7 @@ while (Testing()) {
 	   or DbiError($cursor->err, $cursor->errstr);
     if (!$state && $verbose) {
 	print "Names:\n";
-	for ($i = 0;  $i < @$ref;  $i++) {
+	for (my $i = 0;  $i < @$ref;  $i++) {
 	    print "    ", $$ref[$i], "\n";
 	}
     }
@@ -103,7 +106,7 @@ while (Testing()) {
 	   or DbiError($cursor->err, $cursor->errstr);
     if (!$state && $verbose) {
 	print "Nullable:\n";
-	for ($i = 0;  $i < @$ref;  $i++) {
+	for (my $i = 0;  $i < @$ref;  $i++) {
 	    print "    ", ($$ref[$i] & $COL_NULLABLE) ? "yes" : "no", "\n";
 	}
     }
diff --git a/t/40nulls.t b/t/40nulls.t
index 8a03ab6..bada335 100644
--- a/t/40nulls.t
+++ b/t/40nulls.t
@@ -5,6 +5,8 @@
 #   This is a test for correctly handling NULL values.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $dbdriver $state);
 
 #
 #   Make -w happy
@@ -21,7 +23,7 @@ use DBI;
 use vars qw($COL_NULLABLE);
 
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -44,6 +46,7 @@ sub ServerError() {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $table, $def, $cursor, $rv);
 while (Testing()) {
     #
     #   Connect to the database
diff --git a/t/40numrows.t b/t/40numrows.t
index 605623a..ae3e45e 100644
--- a/t/40numrows.t
+++ b/t/40numrows.t
@@ -5,6 +5,9 @@
 #   This tests, whether the number of rows can be retrieved.
 #
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
+
 $^W = 1;
 $| = 1;
 
@@ -22,7 +25,7 @@ $test_password = '';
 #
 use DBI;
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -56,6 +59,7 @@ sub TrueRows($) {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $table, $def, $cursor, $numrows);
 while (Testing()) {
     #
     #   Connect to the database
diff --git a/t/40prepcached.t b/t/40prepcached.t
index 7af923c..1f34a15 100644
--- a/t/40prepcached.t
+++ b/t/40prepcached.t
@@ -6,6 +6,9 @@
 #   http://rt.cpan.org/Public/Bug/Display.html?id=15186
 #   About re-using statements with prepare_cached().
 
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
+
 $^W = 1;
 $| = 1;
 
@@ -23,7 +26,7 @@ $test_password = '';
 #
 use DBI;
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl", "DBD-~DBD_DRIVER~/t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -57,6 +60,7 @@ sub TrueRows($) {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $table, $def, $cursor, $sth);
 while (Testing()) {
     #
     #   Connect to the database
diff --git a/t/50chopblanks.t b/t/50chopblanks.t
index 75e4b51..d577ee6 100644
--- a/t/50chopblanks.t
+++ b/t/50chopblanks.t
@@ -5,6 +5,7 @@
 #   This driver should check whether 'ChopBlanks' works.
 #
 
+use strict;
 
 #
 #   Make -w happy
diff --git a/t/50commit.t b/t/50commit.t
index 9e2ae94..21f9dbf 100644
--- a/t/50commit.t
+++ b/t/50commit.t
@@ -4,6 +4,10 @@
 #
 #   This is testing the transaction support.
 #
+
+use strict;
+use vars qw($test_dsn $test_user $test_password $mdriver $state);
+
 $^W = 1;
 
 
@@ -12,7 +16,7 @@ $^W = 1;
 #
 require DBI;
 $mdriver = "";
-foreach $file ("lib.pl", "t/lib.pl") {
+foreach my $file ("lib.pl", "t/lib.pl") {
     do $file; if ($@) { print STDERR "Error while executing lib.pl: $@\n";
 			   exit 10;
 		      }
@@ -58,6 +62,7 @@ sub NumRows($$$) {
 #   Main loop; leave this untouched, put tests after creating
 #   the new table.
 #
+my ($dbh, $def, $table, $msg);
 while (Testing()) {
     #
     #   Connect to the database
@@ -105,7 +110,7 @@ while (Testing()) {
 	Test($state or $dbh->do("INSERT INTO $table VALUES (1, 'Jochen')"))
 	    or ErrMsgF("Failed to insert value: err %s, errstr %s.\n",
 		       $dbh->err, $dbh->errstr);
-	my $msg;
+
 	Test($state or !($msg = NumRows($dbh, $table, 1)))
 	    or ErrMsg($msg);
 	Test($state or $dbh->rollback)
diff --git a/t/60metadata.t b/t/60metadata.t
index ec4b17d..f20bb13 100644
--- a/t/60metadata.t
+++ b/t/60metadata.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 27 }
 use DBI;
diff --git a/t/90cppcomments.t b/t/90cppcomments.t
index e45b3e0..c5d5c4b 100644
--- a/t/90cppcomments.t
+++ b/t/90cppcomments.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 use DBI;
 use Fatal qw(open);
diff --git a/t/99cleanup.t b/t/99cleanup.t
index 04003a6..d848f29 100644
--- a/t/99cleanup.t
+++ b/t/99cleanup.t
@@ -1,3 +1,4 @@
+use strict;
 use Test;
 BEGIN { plan tests => 2 }
 ok(-e 'foo');
diff --git a/t/SQLite.dbtest b/t/SQLite.dbtest
index dc6b3b4..6affda7 100644
--- a/t/SQLite.dbtest
+++ b/t/SQLite.dbtest
@@ -4,6 +4,7 @@
 #
 # database specific definitions for a 'CSV' database
 
+use strict;
 
 #   This function generates a mapping of ANSI type names to
 #   database specific type names; it is called by TableDefinition().
diff --git a/t/ak-dbd.t b/t/ak-dbd.t
index c415a86..7d095c2 100644
--- a/t/ak-dbd.t
+++ b/t/ak-dbd.t
@@ -6,6 +6,8 @@
 #   and modify/extend it.
 #
 
+use strict;
+
 $^W = 1;
 $| = 1;