diff --git a/distribution.pm b/distribution.pm
index c5b810086c..ba8ed8a52d 100644
--- a/distribution.pm
+++ b/distribution.pm
@@ -127,7 +127,7 @@ sub script_run ($self, $cmd, @args) {
         my $marker = "; echo $str-\$?-" . ($args{output} ? "Comment: $args{output}" : '');
         if (testapi::is_serial_terminal) {
             testapi::type_string($marker);
-            testapi::wait_serial($cmd . $marker, no_regex => 1, quiet => $args{quiet});
+            testapi::wait_serial($cmd . $marker, no_regex => 1, quiet => $args{quiet}, buffer_size => length($cmd) + 128);
             testapi::type_string("\n");
         }
         else {
diff --git a/t/05-distribution.t b/t/05-distribution.t
index 0cb84b9a84..1a802fbc50 100755
--- a/t/05-distribution.t
+++ b/t/05-distribution.t
@@ -12,6 +12,8 @@ use Test::Warnings qw(:all :report_warnings);
 use Test::Fatal;
 use Test::MockModule;
 
+my @wait_serial_calls;
+
 subtest 'script_run' => sub {
     require distribution;
     my $d = distribution->new;
@@ -33,6 +35,30 @@ subtest 'script_run' => sub {
     lives_ok sub { $d->script_run('foo\&') }, 'escaped terminator is accepted';
     lives_ok sub { $d->script_run('foo && bar') }, 'AND operator is accepted';
     lives_ok sub { $d->script_run('foo "x&"') }, 'quoted & is accepted';
+    $mock_testapi->redefine(wait_serial => sub {
+            my $regexp = shift;
+            push @wait_serial_calls, {
+                regexp => $regexp,
+                timeout => 90,
+                expect_not_found => 0,
+                quiet => undef,
+                no_regex => 0,
+                buffer_size => undef,
+                record_output => undef,
+                @_
+            };
+    });
+    $mock_testapi->redefine(is_serial_terminal => 1);
+    $d->script_run('short_command');
+    # script_run calls wait_serial three times when on a serial
+    # console, the call we want to check - which actually types the
+    # command - is the second
+    my $cmdcall = $wait_serial_calls[1];
+    is $cmdcall->{buffer_size}, 141, 'appropriate buffer size used for short command';
+    @wait_serial_calls = ();
+    $d->script_run('long_command' x 512);
+    $cmdcall = $wait_serial_calls[1];
+    is $cmdcall->{buffer_size}, 6272, 'appropriate buffer size used for long command';
 };
 
 done_testing;