diff --git a/core/model/src/main/java/it/unibz/inf/ontop/model/term/functionsymbol/impl/ObjectStringTemplateFunctionSymbolImpl.java b/core/model/src/main/java/it/unibz/inf/ontop/model/term/functionsymbol/impl/ObjectStringTemplateFunctionSymbolImpl.java
index <HASH>..<HASH> 100644
--- a/core/model/src/main/java/it/unibz/inf/ontop/model/term/functionsymbol/impl/ObjectStringTemplateFunctionSymbolImpl.java
+++ b/core/model/src/main/java/it/unibz/inf/ontop/model/term/functionsymbol/impl/ObjectStringTemplateFunctionSymbolImpl.java
@@ -23,8 +23,7 @@ public abstract class ObjectStringTemplateFunctionSymbolImpl extends FunctionSym
     protected ObjectStringTemplateFunctionSymbolImpl(String template, int arity, TypeFactory typeFactory) {
         super(template, createBaseTypes(arity, typeFactory));
         this.template = template;
-        // TODO: use a DB string instead
-        this.lexicalType = typeFactory.getXsdStringDatatype();
+        this.lexicalType = typeFactory.getDBTypeFactory().getDBStringType();
     }
 
     private static ImmutableList<TermType> createBaseTypes(int arity, TypeFactory typeFactory) {
ObjectStringTemplateFunctionSymbol are now returning a DB string.