diff --git a/ckanext/dcatapchharvest/profiles.py b/ckanext/dcatapchharvest/profiles.py
index 3a266ec..401ba80 100644
--- a/ckanext/dcatapchharvest/profiles.py
+++ b/ckanext/dcatapchharvest/profiles.py
@@ -436,14 +436,14 @@ def _get_groups(self, subject):
                     new_theme_url = dcat_theme_url.replace(
                         OGD_THEMES_URI, CHTHEMES_URI)
                     eu_theme_url = unicode(
-                        eu_theme_mapping[URIRef(new_theme_url)])
+                        eu_theme_mapping[URIRef(new_theme_url)][0])
 
                 # Case 2: We get a dcat-ap.ch theme (the same as the
                 #         opendata.swiss themes, but different base url). Get
                 #         the correct EU theme from the theme mapping.
                 elif dcat_theme_url.startswith(CHTHEMES_URI):
                     eu_theme_url = unicode(
-                        eu_theme_mapping[URIRef(dcat_theme_url)])
+                        eu_theme_mapping[URIRef(dcat_theme_url)][0])
 
                 # Case 3: We get an EU theme and don't need to look it up in
                 #         the mapping.
diff --git a/ckanext/dcatapchharvest/tests/fixtures/catalog-themes.xml b/ckanext/dcatapchharvest/tests/fixtures/catalog-themes.xml
new file mode 100644
index 0000000..44e87bd
--- /dev/null
+++ b/ckanext/dcatapchharvest/tests/fixtures/catalog-themes.xml
@@ -0,0 +1,35 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<rdf:RDF xmlns:foaf="http://xmlns.com/foaf/0.1/" xmlns:hydra="http://www.w3.org/ns/hydra/core#" xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#" xmlns:dcat="http://www.w3.org/ns/dcat#" xmlns:schema="http://schema.org/" xmlns:vcard="http://www.w3.org/2006/vcard/ns#" xmlns:odrs="http://schema.theodi.org/odrs#" xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:dct="http://purl.org/dc/terms/">
+  <dcat:Catalog>
+    <dct:description>BFS - OGD Collection</dct:description>
+    <dct:title>BFS - OGD Collection</dct:title>
+    <dcat:dataset>
+      <dcat:Dataset>
+        <dct:identifier>346252@bundesamt-fur-statistik-bfs</dct:identifier>
+        <dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">1990-12-31T23:00:00Z</dct:issued>
+        <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#dateTime">1991-02-19T23:00:00Z</dct:modified>
+      </dcat:Dataset>
+    </dcat:dataset>
+    <dcat:dataset>
+      <dcat:Dataset>
+        <dct:identifier>346252@bundesamt-fur-statistik-bfs</dct:identifier>
+        <dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#date">1992-12-31</dct:issued>
+        <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#date">1993-02-19</dct:modified>
+      </dcat:Dataset>
+    </dcat:dataset>
+    <dcat:dataset>
+      <dcat:Dataset>
+        <dct:identifier>346252@bundesamt-fur-statistik-bfs</dct:identifier>
+        <dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#gYearMonth">1994-12</dct:issued>
+        <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#gYearMonth">1995-02</dct:modified>
+      </dcat:Dataset>
+    </dcat:dataset>
+    <dcat:dataset>
+      <dcat:Dataset>
+        <dct:identifier>346252@bundesamt-fur-statistik-bfs</dct:identifier>
+        <dct:issued rdf:datatype="http://www.w3.org/2001/XMLSchema#gYear">1996</dct:issued>
+        <dct:modified rdf:datatype="http://www.w3.org/2001/XMLSchema#gYear">1997</dct:modified>
+      </dcat:Dataset>
+    </dcat:dataset>
+  </dcat:Catalog>
+</rdf:RDF>