diff --git a/bin/pt-config-diff b/bin/pt-config-diff
index 32d76421..a08df2a8 100755
--- a/bin/pt-config-diff
+++ b/bin/pt-config-diff
@@ -2171,6 +2171,13 @@ sub _parse_varvals {
             $val = '';
          }
          else {
+            $val =~ s/
+                        \A        # Start of value
+                        (['"])    # Opening quote
+                        (.*)      # Value
+                        \1        # Closing quote
+                        [\n\r]*\z # End of value
+                    /$2/x;
             if ( my ($num, $factor) = $val =~ m/(\d+)([KMGT])b?$/i ) {
                my %factor_for = (
                   k => 1_024,
diff --git a/lib/MySQLConfig.pm b/lib/MySQLConfig.pm
index 5cdf857f..703cada5 100644
--- a/lib/MySQLConfig.pm
+++ b/lib/MySQLConfig.pm
@@ -371,6 +371,13 @@ sub _parse_varvals {
             $val = '';
          }
          else {
+            $val =~ s/
+                        \A        # Start of value
+                        (['"])    # Opening quote
+                        (.*)      # Value
+                        \1        # Closing quote
+                        [\n\r]*\z # End of value
+                    /$2/x;
             if ( my ($num, $factor) = $val =~ m/(\d+)([KMGT])b?$/i ) {
                # value is a size like 1k, 16M, etc.
                my %factor_for = (
diff --git a/t/lib/MySQLConfigComparer.t b/t/lib/MySQLConfigComparer.t
index 46b1d5c9..f3f04e5c 100644
--- a/t/lib/MySQLConfigComparer.t
+++ b/t/lib/MySQLConfigComparer.t
@@ -9,7 +9,7 @@ BEGIN {
 use strict;
 use warnings FATAL => 'all';
 use English qw(-no_match_vars);
-use Test::More tests => 16;
+use Test::More;
 
 use TextResultSetParser();
 use MySQLConfigComparer;
@@ -369,6 +369,29 @@ $c2 = new MySQLConfig(
    ) or print Dumper($diff);
 }
 
+# ############################################################################
+# https://bugs.launchpad.net/percona-toolkit/+bug/889739
+# pt-config-diff doesn't diff quoted strings properly
+# ############################################################################
+$c1 = new MySQLConfig(
+   file                => "$trunk/$sample/quoted_cnf.txt",
+   TextResultSetParser => $trp,
+);
+$c2 = new MySQLConfig(
+   file                => "$trunk/$sample/unquoted_cnf.txt",
+   TextResultSetParser => $trp,
+);
+{
+    my $diff = $cc->diff(
+      configs => [$c1, $c2],
+    );
+
+    is_deeply(
+        $diff,
+        undef,
+        "Values are the same regardless of quoting"
+    ) or diag(Dumper($diff));
+}
 # #############################################################################
 # Done.
 # #############################################################################
@@ -382,4 +405,5 @@ like(
    qr/Complete test coverage/,
    '_d() works'
 );
-exit;
+
+done_testing;
diff --git a/t/lib/samples/configs/quoted_cnf.txt b/t/lib/samples/configs/quoted_cnf.txt
new file mode 100644
index 00000000..2103679d
--- /dev/null
+++ b/t/lib/samples/configs/quoted_cnf.txt
@@ -0,0 +1,6 @@
+[client]
+port        = 3306
+socket      = /var/run/mysqld/mysqld.sock
+
+[mysqld]
+init-connect='SET NAMES utf8'
diff --git a/t/lib/samples/configs/unquoted_cnf.txt b/t/lib/samples/configs/unquoted_cnf.txt
new file mode 100644
index 00000000..5ecd72d9
--- /dev/null
+++ b/t/lib/samples/configs/unquoted_cnf.txt
@@ -0,0 +1,6 @@
+[client]
+port        = 3306
+socket      = /var/run/mysqld/mysqld.sock
+
+[mysqld]
+init-connect=SET NAMES utf8
diff --git a/t/lib/samples/empty.txt b/t/lib/samples/empty.txt
new file mode 100644
index 00000000..e69de29b