diff --git a/test-cases/RMLSTC0005a/Friends-NULL.csv b/test-cases/RMLSTC0005a/Friends-NULL.csv
index ce0c558..ab5f192 100644
--- a/test-cases/RMLSTC0005a/Friends-NULL.csv
+++ b/test-cases/RMLSTC0005a/Friends-NULL.csv
@@ -1,7 +1,7 @@
-id, name, age
-0, Monica Geller, 33
-1, Rachel Green, 34
-2, Joey Tribbiani, 35
-3, Chandler Bing, 36
-4, Ross Geller, 37
-5,,
+id;name;age
+0;Monica Geller;33
+1;Rachel Green;34
+2;Joey Tribbiani;35
+3;Chandler Bing;36
+4;Ross Geller;37
+5;;
diff --git a/test-cases/RMLSTC0005a/mapping.ttl b/test-cases/RMLSTC0005a/mapping.ttl
index f698e8e..b8b05ab 100644
--- a/test-cases/RMLSTC0005a/mapping.ttl
+++ b/test-cases/RMLSTC0005a/mapping.ttl
@@ -5,7 +5,7 @@
 @base <http://example.com/rules/> .
 
 <#CSVWSourceAccess> a rml:Source, csvw:Table;
-  csvw:url "file://./Friends.csv";
+  csvw:url "file://./Friends-NULL.csv";
   csvw:dialect [ a csvw:Dialect;
     csvw:delimiter ";";
     csvw:encoding "UTF-8";
@@ -19,6 +19,7 @@
 <#TriplesMap> a rml:TriplesMap;
   rml:logicalSource [ a rml:LogicalSource;
     rml:source <#CSVWSourceAccess>;
+    rml:referenceFormulation rml:CSV;
   ];
   rml:subjectMap [ a rml:SubjectMap;
     rml:template "http://example.org/{id}";
diff --git a/test-cases/RMLSTC0005b/Friends.csv b/test-cases/RMLSTC0005b/Friends.csv
index ebd9181..0d40425 100644
Binary files a/test-cases/RMLSTC0005b/Friends.csv and b/test-cases/RMLSTC0005b/Friends.csv differ
diff --git a/test-cases/RMLSTC0005b/mapping.ttl b/test-cases/RMLSTC0005b/mapping.ttl
index 499add7..66b67ef 100644
--- a/test-cases/RMLSTC0005b/mapping.ttl
+++ b/test-cases/RMLSTC0005b/mapping.ttl
@@ -18,6 +18,7 @@
 <#TriplesMap> a rml:TriplesMap;
   rml:logicalSource [ a rml:LogicalSource;
     rml:source <#CSVWSourceAccess>;
+    rml:referenceFormulation rml:CSV;
   ];
   rml:subjectMap [ a rml:SubjectMap;
     rml:template "http://example.org/{id}";