diff --git a/t/02_logon.t b/t/02_logon.t
index 64d8dda..5e14563 100644
--- a/t/02_logon.t
+++ b/t/02_logon.t
@@ -7,7 +7,9 @@ use SQLiteTest qw/connect_ok @CALL_FUNCS/;
 use Test::More;
 use if -d ".git", "Test::FailWarnings";
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 my $show_diag = 0;
 foreach my $call_func (@CALL_FUNCS) {
diff --git a/t/12_unicode.t b/t/12_unicode.t
index 95c5a02..84705d8 100644
--- a/t/12_unicode.t
+++ b/t/12_unicode.t
@@ -8,7 +8,9 @@ use SQLiteTest;
 use Test::More;
 use if -d ".git", "Test::FailWarnings";
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 BEGIN { requires_unicode_support() }
 
diff --git a/t/13_create_collation.t b/t/13_create_collation.t
index 3aa6985..28612f5 100644
--- a/t/13_create_collation.t
+++ b/t/13_create_collation.t
@@ -7,8 +7,9 @@ use Test::More;
 use if -d ".git", "Test::FailWarnings";
 use Encode qw/decode/;
 use DBD::SQLite;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 BEGIN { requires_unicode_support(); }
 
@@ -73,7 +74,7 @@ is($DBD::SQLite::COLLATION{foo}, \&by_num_desc, "overridden collation");
 
 foreach my $call_func (@CALL_FUNCS) {
 
-  for my $unicode_opt ( DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES, DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
+  for my $unicode_opt (DBD_SQLITE_STRING_MODE_BYTES, DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
 
     # connect
     my $dbh = connect_ok( RaiseError => 1, sqlite_string_mode => $unicode_opt );
@@ -86,7 +87,7 @@ foreach my $call_func (@CALL_FUNCS) {
 	HAT hâôer 
 	féôu fêôe fèöe ferme
      };
-    if ($unicode_opt != DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES) {
+    if ($unicode_opt != DBD_SQLITE_STRING_MODE_BYTES) {
       utf8::upgrade($_) foreach @words;
     }
 
diff --git a/t/33_non_latin_path.t b/t/33_non_latin_path.t
index a55600e..f13f0eb 100644
--- a/t/33_non_latin_path.t
+++ b/t/33_non_latin_path.t
@@ -10,7 +10,9 @@ use if -d ".git", "Test::FailWarnings";
 use File::Temp ();
 use File::Spec::Functions ':ALL';
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 BEGIN { requires_unicode_support() }
 
diff --git a/t/37_regexp.t b/t/37_regexp.t
index b5e51ad..13d7a3d 100644
--- a/t/37_regexp.t
+++ b/t/37_regexp.t
@@ -28,10 +28,11 @@ BEGIN {
 use locale;
 
 use DBD::SQLite;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
 
 foreach my $call_func (@CALL_FUNCS) {
 
-  for my $string_mode (DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES, DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
+  for my $string_mode (DBD_SQLITE_STRING_MODE_BYTES, DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
 
     # connect
     my $dbh = connect_ok( RaiseError => 1, sqlite_string_mode => $string_mode );
@@ -43,7 +44,7 @@ foreach my $call_func (@CALL_FUNCS) {
 
     # populate test data
     my @vals = @words;
-    if ($string_mode == DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES) {
+    if ($string_mode == DBD_SQLITE_STRING_MODE_BYTES) {
       utf8::upgrade($_) foreach @vals;
     }
 
diff --git a/t/43_fts3.t b/t/43_fts3.t
index b57eb4a..32340c1 100644
--- a/t/43_fts3.t
+++ b/t/43_fts3.t
@@ -6,7 +6,7 @@ use SQLiteTest;
 use Test::More;
 use if -d ".git", "Test::FailWarnings";
 use DBD::SQLite;
-
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
 
 my @texts = ("il était une bergère",
              "qui gardait ses moutons",
@@ -59,7 +59,7 @@ sub Unicode_Word_tokenizer { # see also: Search::Tokenizer
 
 use DBD::SQLite;
 
-for my $string_mode (DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES, DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
+for my $string_mode (DBD_SQLITE_STRING_MODE_BYTES, DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
 
   # connect
   my $dbh = connect_ok( RaiseError => 1, sqlite_string_mode => $string_mode );
@@ -106,7 +106,7 @@ for my $string_mode (DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES, DBD::
     # the 'offsets' function should return integer offsets for the words in the MATCH query
     my $sql_offsets = "SELECT offsets(try_$fts) FROM try_$fts WHERE content MATCH ?";
     $result = $dbh->selectcol_arrayref($sql_offsets, undef, 'une');
-    my $offset_une = $string_mode == DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT ? $ix_une_utf8 : $ix_une_native;
+    my $offset_une = $string_mode == DBD_SQLITE_STRING_MODE_UNICODE_STRICT ? $ix_une_utf8 : $ix_une_native;
     my $expected_offsets = "0 0 $offset_une 3";
     is_deeply($result, [$expected_offsets], "offsets ($fts, string_mode=$string_mode)");
 
diff --git a/t/62_regexp_multibyte_char_class.t b/t/62_regexp_multibyte_char_class.t
index 6e13a67..c9ce0ed 100644
--- a/t/62_regexp_multibyte_char_class.t
+++ b/t/62_regexp_multibyte_char_class.t
@@ -7,6 +7,8 @@ use Test::More;
 
 BEGIN { requires_unicode_support() }
 
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
 # special case for multibyte (non-ASCII) character class,
 # which only works correctly under the unicode mode
 my @words = ("\x{e3}\x{83}\x{86}\x{e3}\x{82}\x{b9}\x{e3}\x{83}\x{88}", "\x{e3}\x{83}\x{86}\x{e3}\x{83}\x{b3}\x{e3}\x{83}\x{88}"); # テスト テント
@@ -15,15 +17,15 @@ my $regex = "\x{e3}\x{83}\x{86}[\x{e3}\x{82}\x{b9}\x{e3}\x{83}\x{b3}]\x{e3}\x{83
 
 foreach my $call_func (@CALL_FUNCS) {
 
-  for my $use_unicode (0, 1) {
+  for my $string_mode (DBD_SQLITE_STRING_MODE_PV, DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
 
     # connect
-    my $dbh = connect_ok( RaiseError => 1, sqlite_unicode => $use_unicode );
+    my $dbh = connect_ok( RaiseError => 1, sqlite_string_mode => $string_mode );
 
     # populate test data
     my @vals = @words;
     my $re = $regex;
-    if ($use_unicode) {
+    if ($string_mode == DBD_SQLITE_STRING_MODE_UNICODE_STRICT) {
       utf8::decode($_) foreach @vals;
       utf8::decode($re);
     }
diff --git a/t/rt_25371_asymmetric_unicode.t b/t/rt_25371_asymmetric_unicode.t
index 6442cc2..a65b92d 100644
--- a/t/rt_25371_asymmetric_unicode.t
+++ b/t/rt_25371_asymmetric_unicode.t
@@ -5,7 +5,9 @@ use SQLiteTest;
 use Test::More;
 use if -d ".git", "Test::FailWarnings";
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 BEGIN { requires_unicode_support(); }
 
diff --git a/t/rt_25924_user_defined_func_unicode.t b/t/rt_25924_user_defined_func_unicode.t
index fbec113..63f8026 100644
--- a/t/rt_25924_user_defined_func_unicode.t
+++ b/t/rt_25924_user_defined_func_unicode.t
@@ -5,7 +5,9 @@ use SQLiteTest;
 use Test::More;
 use if -d ".git", "Test::FailWarnings";
 
-my $unicode_opt = DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $unicode_opt = DBD_SQLITE_STRING_MODE_UNICODE_STRICT;
 
 BEGIN { requires_unicode_support() }
 
diff --git a/t/rt_71311_bind_col_and_unicode.t b/t/rt_71311_bind_col_and_unicode.t
index 324e5ef..132d1ba 100644
--- a/t/rt_71311_bind_col_and_unicode.t
+++ b/t/rt_71311_bind_col_and_unicode.t
@@ -6,11 +6,11 @@ use Test::More;
 use if -d ".git", "Test::FailWarnings";
 use DBI qw/:sql_types/;
 
-use DBD::SQLite::Constants;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
 
 BEGIN{ requires_unicode_support(); }
 
-my $dbh = connect_ok(sqlite_string_mode => DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT);
+my $dbh = connect_ok(sqlite_string_mode => DBD_SQLITE_STRING_MODE_UNICODE_STRICT);
 $dbh->do('create table test1 (id integer, b blob)');
 
 my $blob = "\x{82}\x{A0}";
diff --git a/t/rt_78833_utf8_flag_for_column_names.t b/t/rt_78833_utf8_flag_for_column_names.t
index 3fcacd7..17b8dd0 100644
--- a/t/rt_78833_utf8_flag_for_column_names.t
+++ b/t/rt_78833_utf8_flag_for_column_names.t
@@ -6,7 +6,7 @@ use Test::More;
 use if -d ".git", "Test::FailWarnings";
 use Encode;
 
-use DBD::SQLite::Constants;
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
 
 BEGIN { requires_unicode_support() }
 
@@ -22,7 +22,7 @@ sub unicode_test {
 
     { # tests for an environment where everything is encoded
 
-        my $dbh = connect_ok(sqlite_string_mode => DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_BYTES);
+        my $dbh = connect_ok(sqlite_string_mode => DBD_SQLITE_STRING_MODE_BYTES);
         $dbh->do("pragma foreign_keys = on");
         my $unicode_quoted = $dbh->quote_identifier($unicode_encoded);
         $dbh->do("create table $unicode_quoted (id, $unicode_quoted primary key)");
@@ -89,7 +89,7 @@ sub unicode_test {
     }
 
     { # tests for an environment where everything is decoded
-        my $dbh = connect_ok(sqlite_string_mode => DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_STRICT);
+        my $dbh = connect_ok(sqlite_string_mode => DBD_SQLITE_STRING_MODE_UNICODE_STRICT);
         $dbh->do("pragma foreign_keys = on");
         my $unicode_quoted = $dbh->quote_identifier($unicode);
         $dbh->do("create table $unicode_quoted (id, $unicode_quoted primary key)");
diff --git a/t/rt_96877_unicode_statements.t b/t/rt_96877_unicode_statements.t
index 437a753..4df710b 100644
--- a/t/rt_96877_unicode_statements.t
+++ b/t/rt_96877_unicode_statements.t
@@ -11,8 +11,10 @@ use if -d ".git", "Test::FailWarnings";
 
 BEGIN { requires_unicode_support() }
 
-my $dbh = connect_ok( sqlite_string_mode => DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_NAIVE );
-is( $dbh->{sqlite_string_mode}, DBD::SQLite::Constants::DBD_SQLITE_STRING_MODE_UNICODE_NAIVE, 'Unicode is on' );
+use DBD::SQLite::Constants ':dbd_sqlite_string_mode';
+
+my $dbh = connect_ok( sqlite_string_mode => DBD_SQLITE_STRING_MODE_UNICODE_NAIVE );
+is( $dbh->{sqlite_string_mode}, DBD_SQLITE_STRING_MODE_UNICODE_NAIVE, 'Unicode is on' );
 
 ok( $dbh->do(<<'END_SQL'), 'CREATE TABLE' );
 CREATE TABLE foo (