diff --git a/pygal/adapters.py b/pygal/adapters.py
index a952eb4..e7bca90 100644
--- a/pygal/adapters.py
+++ b/pygal/adapters.py
@@ -43,18 +43,6 @@ def none_to_zero(x):
     return x or 0
 
 
-def int_to_country(x):
-    # This is used for test compatibility
-    if isinstance(x, Number):
-        try:
-            x = int(x)
-        except:
-            return x
-        if x >= 0 and x < len(COUNTRIES):
-            return list(COUNTRIES.keys())[x]
-    return x
-
-
 def date(x):
     # Make int work for date graphs by counting days number from now
     if isinstance(x, Number):
diff --git a/pygal/graph/worldmap.py b/pygal/graph/worldmap.py
index ad5e295..4f637ad 100644
--- a/pygal/graph/worldmap.py
+++ b/pygal/graph/worldmap.py
@@ -25,7 +25,6 @@ from __future__ import division
 from pygal.util import cut, cached_property, decorate
 from pygal.graph.graph import Graph
 from pygal.i18n import COUNTRIES
-from pygal.adapters import int_to_country
 from lxml import etree
 import os
 
@@ -40,7 +39,6 @@ class Worldmap(Graph):
     _dual = True
     x_labels = list(COUNTRIES.keys())
     country_names = COUNTRIES
-    _adapters = [int_to_country]
 
     @cached_property
     def countries(self):
diff --git a/pygal/test/__init__.py b/pygal/test/__init__.py
index fdac292..f73533b 100644
--- a/pygal/test/__init__.py
+++ b/pygal/test/__init__.py
@@ -20,6 +20,8 @@
 import pygal
 from pygal.util import cut
 from datetime import datetime
+from pygal.i18n import COUNTRIES
+COUNTRY_KEYS = list(COUNTRIES.keys())
 
 
 def get_data(i):
@@ -44,12 +46,21 @@ def pytest_generate_tests(metafunc):
 
 
 def adapt(chart, data):
+    if isinstance(chart, pygal.DateY):
+        # Convert to a credible datetime
+        return list(map(
+            lambda t:
+            (datetime.fromtimestamp(1360000000 + t[0] * 987654)
+             if t[0] is not None else None, t[1]), data))
+
     if isinstance(chart, pygal.XY):
-        if isinstance(chart, pygal.DateY):
-            # Convert to a credible datetime
-            return datetime.fromtimestamp(1360000000 + data * 987654)
         return data
-    return cut(data)
+
+    data = cut(data)
+    if isinstance(chart, pygal.Worldmap):
+        return list(map(lambda x: COUNTRY_KEYS[x % len(COUNTRIES)]
+                        if x is not None else None, data))
+    return data
 
 
 def make_data(chart, datas):