diff --git a/Changes b/Changes
index e901190..c672347 100644
--- a/Changes
+++ b/Changes
@@ -2,6 +2,9 @@ Revision history for MooseX-Types
 
 {{$NEXT}}
 
+        - re-added the is_Foo and to_Food refactoring after resolving
+          RT #119534
+
 0.50      2017-02-07 18:59:30Z
         - reverted the is_Foo and to_Foo refactoring again temporarily to
           resolve issues with Sub::Defer
@@ -9,7 +12,7 @@ Revision history for MooseX-Types
 0.49      2016-12-23 00:12:12Z
         - made the exported is_Foo and to_Foo subs much faster, especially for
           type constraints which can be inlined. (Dave Rolsky) [reverted in
-          0.50)
+          0.50]
 
 0.48      2016-12-07 01:15:14Z
         - reverted is_Foo and to_Foo refactoring [from 0.47] for now, so they
diff --git a/lib/MooseX/Types.pm b/lib/MooseX/Types.pm
index 0988f43..8b049f3 100644
--- a/lib/MooseX/Types.pm
+++ b/lib/MooseX/Types.pm
@@ -12,6 +12,7 @@ use MooseX::Types::Util               qw( filter_tags );
 use MooseX::Types::UndefinedType;
 use MooseX::Types::CheckedUtilExports ();
 use Carp::Clan                        qw( ^MooseX::Types );
+use Sub::Defer                        qw( defer_sub );
 use Sub::Name;
 use Scalar::Util                      qw( reftype );
 use Sub::Exporter::ForMethods 0.100052 'method_installer';  # for 'rebless'
@@ -485,18 +486,23 @@ This generates a coercion handler function, e.g. C<to_Int($value)>.
 =cut
 
 sub coercion_export_generator {
-    my ($class, $type, $full, $undef_msg) = @_;
-    return sub {
+    my ($class, $sub_name, $type, $full, $undef_msg) = @_;
+    return defer_sub $sub_name, sub {
         my ($value) = @_;
 
         # we need a type object
-        my $tobj = find_type_constraint($full) or croak $undef_msg;
-        my $return = $tobj->coerce($value);
+        my $tobj = find_type_constraint($full);
 
-        # non-successful coercion returns false
-        return unless $tobj->check($return);
+        return sub {
+            croak $undef_msg unless $tobj;
 
-        return $return;
+            my $return = $tobj->coerce($_[0]);
+
+            # non-successful coercion returns false
+            return unless $tobj->check($return);
+
+            return $return;
+        };
     }
 }
 
@@ -507,14 +513,21 @@ Generates a constraint check closure, e.g. C<is_Int($value)>.
 =cut
 
 sub check_export_generator {
-    my ($class, $type, $full, $undef_msg) = @_;
-    return sub {
+    my ($class, $sub_name, $type, $full, $undef_msg) = @_;
+
+    return defer_sub $sub_name, sub {
         my ($value) = @_;
 
         # we need a type object
-        my $tobj = find_type_constraint($full) or croak $undef_msg;
-
-        return $tobj->check($value);
+        my $tobj = find_type_constraint($full);
+
+        # This method will actually compile an inlined sub if possible. If
+        # not, it will return something like sub { $tobj->check($_[0]) }
+        #
+        # If $tobj is undef, we delay the croaking until the check is
+        # actually used for backward compatibility reasons. See
+        # RT #119534.
+        return $tobj ? $tobj->_compiled_type_constraint : sub { croak $undef_msg};
     }
 }
 
diff --git a/lib/MooseX/Types/Base.pm b/lib/MooseX/Types/Base.pm
index 3600f7d..0eaccc4 100644
--- a/lib/MooseX/Types/Base.pm
+++ b/lib/MooseX/Types/Base.pm
@@ -53,8 +53,18 @@ sub import {
     # determine the wrapper, -into is supported for compatibility reasons
     my $wrapper = $options->{ -wrapper } || 'MooseX::Types';
 
-    $args[0]->{into} = $options->{ -into }
-        if exists $options->{ -into };
+    # It's a little gross to calculate the calling package here when
+    # Sub::Exporter is going to do it again, but we need to give Sub::Defer a
+    # fully qualified name if we give it a name at all, and we want to give it
+    # a name. Otherwise it guesses at the name and will use its caller, which
+    # in this case ends up being MooseX::Types, which is wrong.
+    my $into;
+    if (exists $options->{ -into }) {
+        $into = $args[0]->{into} = $options->{ -into }
+    }
+    else {
+        $into = caller(($options->{into_level} || 0) + 1)
+    }
 
     my %ex_util;
 
@@ -79,7 +89,7 @@ sub import {
         my $check_name = "is_${type_short}";
         push @{ $ex_spec{exports} },
             $check_name,
-            sub { $wrapper->check_export_generator($type_short, $type_full, $undef_msg) };
+            sub { $wrapper->check_export_generator("${into}::$check_name", $type_short, $type_full, $undef_msg) };
 
         # only export coercion helper if full (for libraries) or coercion is defined
         next TYPE
@@ -89,7 +99,7 @@ sub import {
         my $coercion_name = "to_${type_short}";
         push @{ $ex_spec{exports} },
             $coercion_name,
-            sub { $wrapper->coercion_export_generator($type_short, $type_full, $undef_msg) };
+            sub { $wrapper->coercion_export_generator("${into}::$coercion_name", $type_short, $type_full, $undef_msg) };
         $ex_util{ $type_short }{to}++;  # shortcut to remember this exists
     }
 
diff --git a/t/27-sub-defer.t b/t/27-sub-defer.t
new file mode 100644
index 0000000..0562e2f
--- /dev/null
+++ b/t/27-sub-defer.t
@@ -0,0 +1,41 @@
+use strict;
+use warnings;
+
+use Test::More 0.88;
+use if $ENV{AUTHOR_TESTING}, 'Test::Warnings';
+
+use Test::Fatal;
+use B::Deparse;
+use MooseX::Types::Moose qw( Int );
+use Sub::Defer qw( undefer_all );
+
+like(
+    B::Deparse->new->coderef2text( \&is_Int ),
+    qr/package Sub::Defer/,
+    'is_Int sub has not yet been undeferred'
+);
+is(
+    exception { undefer_all() },
+    undef,
+    'Sub::Defer::undefer_all works with subs exported by MooseX::Types'
+);
+unlike(
+    B::Deparse->new->coderef2text( \&is_Int ),
+    qr/package Sub::Defer/,
+    'is_Int sub is now undeferred'
+);
+
+{
+    package MyTypes;
+
+    use MooseX::Types -declare => ['Unused'];
+
+}
+
+is(
+    exception { undefer_all() },
+    undef,
+    'Sub::Defer::undefer_all does not throw an exception with unused type declaration'
+);
+
+done_testing();