diff --git a/auth_basic.t b/auth_basic.t
index ed08ca7e..6f7270b0 100644
--- a/auth_basic.t
+++ b/auth_basic.t
@@ -53,7 +53,7 @@ http {
                 # prepended with conf_prefix
                 auth_basic_user_file $arg_f;
                 alias %%TESTDIR%%/;
-	    }
+            }
         }
     }
 }
diff --git a/h2_error_page.t b/h2_error_page.t
index 7e3de5a7..e41c42e1 100644
--- a/h2_error_page.t
+++ b/h2_error_page.t
@@ -72,9 +72,9 @@ my ($sid, $frames, $frame);
 
 my $s1 = Test::Nginx::HTTP2->new();
 $sid = $s1->new_stream({ headers => [
-        { name => ':method', value => 'GET' },
-        { name => ':path', value => '/' },
-        { name => ':authority', value => 'localhost' }]});
+	{ name => ':method', value => 'GET' },
+	{ name => ':path', value => '/' },
+	{ name => ':authority', value => 'localhost' }]});
 $frames = $s1->read(all => [{ type => 'RST_STREAM' }]);
 
 ($frame) = grep { $_->{type} eq "RST_STREAM" } @$frames;
diff --git a/h2_request_body_extra.t b/h2_request_body_extra.t
index 64aceae9..4bd60593 100644
--- a/h2_request_body_extra.t
+++ b/h2_request_body_extra.t
@@ -223,7 +223,7 @@ like(http2_get_body_multi_nolen('/unbuf/', '0123456789' x 128),
 	'body unbuf multi nolen in two buffers');
 like(http2_get_body_multi_nolen('/unbuf/', '0123456789' x 512),
 	qr/(?!.*x-unbuf-file.*)x-body-file/ms,
-        'body unbuf multi nolen in file');
+	'body unbuf multi nolen in file');
 like(read_body_file(http2_get_body_multi_nolen('/unbuf/file',
 	'0123456789' x 512)), qr/^(0123456789){512}$/s,
 	'body unbuf multi nolen in file only');
diff --git a/h3_request_body_extra.t b/h3_request_body_extra.t
index 2273d09a..d5723b3b 100644
--- a/h3_request_body_extra.t
+++ b/h3_request_body_extra.t
@@ -243,7 +243,7 @@ like(http3_get_body_multi_nolen('/unbuf/', '0123456789' x 128),
 	'body unbuf multi nolen in two buffers');
 like(http3_get_body_multi_nolen('/unbuf/', '0123456789' x 512),
 	qr/(?!.*x-unbuf-file.*)x-body-file/ms,
-        'body unbuf multi nolen in file');
+	'body unbuf multi nolen in file');
 like(read_body_file(http3_get_body_multi_nolen('/unbuf/file',
 	'0123456789' x 512)), qr/^(0123456789){512}$/s,
 	'body unbuf multi nolen in file only');
diff --git a/mail_ssl.t b/mail_ssl.t
index 0fed3bb6..8fd68b95 100644
--- a/mail_ssl.t
+++ b/mail_ssl.t
@@ -45,7 +45,7 @@ mail {
 
     ssl_password_file password;
 
-    auth_http  http://127.0.0.1:8080;	# unused
+    auth_http  http://127.0.0.1:8080; # unused
 
     server {
         listen             127.0.0.1:8143;
diff --git a/proxy_cache_manager.t b/proxy_cache_manager.t
index 058474cf..ba4ec10b 100644
--- a/proxy_cache_manager.t
+++ b/proxy_cache_manager.t
@@ -25,7 +25,7 @@ select STDOUT; $| = 1;
 plan(skip_all => 'long test') unless $ENV{TEST_NGINX_UNSAFE};
 
 plan(skip_all => 'page size is not appropriate') unless
-        POSIX::sysconf(&POSIX::_SC_PAGESIZE) == 4096;
+	POSIX::sysconf(&POSIX::_SC_PAGESIZE) == 4096;
 
 my $t = Test::Nginx->new()->has(qw/http proxy cache/)
 	->write_file_expand('nginx.conf', <<'EOF');
diff --git a/scgi_extra_data.t b/scgi_extra_data.t
index 249d7e11..4ff3e97b 100644
--- a/scgi_extra_data.t
+++ b/scgi_extra_data.t
@@ -142,7 +142,7 @@ sub scgi_daemon {
 	while (my $request = $scgi->accept()) {
 		eval { $request->read_env(); };
 		next if $@;
-		
+
 		$uri = $request->env->{REQUEST_URI};
 		$uri =~ s!^/unbuf!!;
 
diff --git a/slice.t b/slice.t
index 26dba3fd..69b6f6eb 100644
--- a/slice.t
+++ b/slice.t
@@ -114,7 +114,7 @@ http {
         location / {
             if ($http_range = "") {
                 set $limit_rate 100;
-	    }
+            }
         }
     }
 }
diff --git a/ssl.t b/ssl.t
index 6055e083..2da10a53 100644
--- a/ssl.t
+++ b/ssl.t
@@ -339,9 +339,9 @@ sub get_ssl_shutdown {
 
 	$s->blocking(0);
 	while (IO::Select->new($s)->can_read(8)) {
-                my $n = $s->sysread(my $buf, 16384);
-                next if !defined $n && $!{EWOULDBLOCK};
-                last;
+		my $n = $s->sysread(my $buf, 16384);
+		next if !defined $n && $!{EWOULDBLOCK};
+		last;
 	}
 	$s->blocking(1);
 
diff --git a/ssl_certificates.t b/ssl_certificates.t
index 4697af9a..e640e8e3 100644
--- a/ssl_certificates.t
+++ b/ssl_certificates.t
@@ -75,7 +75,7 @@ my $d = $t->testdir();
 system("openssl ecparam -genkey -out $d/ec.key -name prime256v1 "
 	. ">>$d/openssl.out 2>&1") == 0 or die "Can't create EC pem: $!\n";
 system("openssl genrsa -out $d/rsa.key 2048 >>$d/openssl.out 2>&1") == 0
-        or die "Can't create RSA pem: $!\n";
+	or die "Can't create RSA pem: $!\n";
 
 foreach my $name ('ec', 'rsa') {
 	system("openssl req -x509 -new -key $d/$name.key "
diff --git a/ssl_sni_sessions.t b/ssl_sni_sessions.t
index 7ff5fa0a..6d5f6ebd 100644
--- a/ssl_sni_sessions.t
+++ b/ssl_sni_sessions.t
@@ -115,7 +115,7 @@ plan(skip_all => 'no TLSv1.3 sessions, old Net::SSLeay')
 plan(skip_all => 'no TLSv1.3 sessions, old IO::Socket::SSL')
 	if $IO::Socket::SSL::VERSION < 2.061 && test_tls13();
 plan(skip_all => 'no TLSv1.3 sessions in LibreSSL')
-        if $t->has_module('LibreSSL') && test_tls13();
+	if $t->has_module('LibreSSL') && test_tls13();
 plan(skip_all => 'no TLS 1.3 session cache in BoringSSL')
 	if $t->has_module('BoringSSL') && test_tls13();