diff --git a/tests/datadoc/test_dataset.py b/tests/datadoc/test_dataset.py
index 75de722a..c7936123 100644
--- a/tests/datadoc/test_dataset.py
+++ b/tests/datadoc/test_dataset.py
@@ -756,6 +756,7 @@ def test_datadoc():
     # Test load dict-representation of a dataset from the triplestore
     SEM = ts.namespaces["sem"]
     SEMDATA = ts.namespaces["semdata"]
+    ts.bind("par", "http://sintef.no/dlite/parser#")
     iri = SEMDATA["SEM_cement_batch2/77600-23-001/77600-23-001_5kV_400x_m001"]
     d = acquire(ts, iri, use_sparql=False)
     assert d["@id"] == iri
@@ -886,6 +887,11 @@ def test_datadoc():
         SEMDATA.SEM_cement_batch2,
     ]
 
+    # Search on criterion when the value is an individual
+    assert search(ts, criteria={"distribution.parser": "par:Hitachi"}) == [
+        SEMDATA["SEM_cement_batch2/77600-23-001/77600-23-001_5kV_400x_m001"],
+    ]
+
     title = "Nested series of SEM images of cement batch2"
     dset = [SEMDATA.SEM_cement_batch2]
     # Search with predefined keyword
diff --git a/tripper/datadoc/dataset.py b/tripper/datadoc/dataset.py
index cfc64c4c..24b49664 100644
--- a/tripper/datadoc/dataset.py
+++ b/tripper/datadoc/dataset.py
@@ -1466,7 +1466,7 @@ def make_query(
     context = get_context(keywords=keywords)
     context._create_caches()  # pylint: disable=protected-access
     expanded = context._expanded  # pylint: disable=protected-access
-
+    # print("expanded", expanded)
     # Add prefixes to triplestore
     ts.namespaces.update(keywords.get_prefixes())
 
@@ -1506,6 +1506,8 @@ def add_crit(k, v, regex=False, s="iri"):
         """Add criteria to SPARQL query."""
         nonlocal n
         key = f"@{k[1:]}" if k.startswith("_") else k
+        # print("key", key)
+        # print("value", v)
         if isinstance(v, list):
             for ele in v:
                 add_crit(key, ele, regex=regex, s=s)
@@ -1539,7 +1541,7 @@ def add_crit(k, v, regex=False, s="iri"):
                     f"FILTER REGEX(STR(?{var}), {value}{flags_arg}) ."
                 )
             else:
-                filters.append(f"FILTER(STR(?{var}) = {value}) .")
+                filters.append(f"FILTER(?{var} = {value}) .")
 
     for k, v in criteria.items():
         add_crit(k, v)
@@ -1558,6 +1560,10 @@ def add_crit(k, v, regex=False, s="iri"):
       {where_statements}
     }}
     """
+    # print("---")
+    # print(query)
+    # print("---")
+
     return query