diff --git a/core/src/main/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolver.java b/core/src/main/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolver.java
index 40d2791..c9cfd7e 100644
--- a/core/src/main/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolver.java
+++ b/core/src/main/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolver.java
@@ -27,6 +27,7 @@
 import org.semanticweb.owlapi.model.OWLEntity;
 import org.semanticweb.owlapi.model.OWLOntology;
 import org.semanticweb.owlapi.model.parameters.Imports;
+import org.semanticweb.owlapi.vocab.OWLRDFVocabulary;
 
 /**
  * An object to resolve labels into identifiers using the {@code rdfs:label}
@@ -63,6 +64,22 @@ public String resolve(String label) {
             }
             resolved = idMap.get(label);
         }
+
+        // We accept "is_a" as a shortcut for "rdfs:subClassOf". We check for it only
+        // after everything else, to avoid masking another class or relation in the
+        // ontology that would have a "is_a" label (admittedly such a label would be a
+        // very bad idea, but just in case).
+        // FIXME: Ideally, "is_a" should be resolved into "rdfs:subClassOf" when it is
+        // used between classes, and into "rdfs:subPropertyOf" when it is used between
+        // properties. But providing the resolver with the necessary context to do that
+        // would complicate things too much for arguably little gain (it is assumed that
+        // most uses of "is_a" will be between classes). So, "is_a" can only be used as
+        // a shortcut when dealing with classes. For subsumption relations between
+        // properties, "rdfs:subPropertyOf" should be used explicitly.
+        if ( resolved == null && label.equals("is_a") ) {
+            resolved = OWLRDFVocabulary.RDFS_SUBCLASS_OF.getIRI().toString();
+        }
+
         return resolved;
     }
 
diff --git a/core/src/test/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolverTest.java b/core/src/test/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolverTest.java
index 43e3b60..2c4147d 100644
--- a/core/src/test/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolverTest.java
+++ b/core/src/test/java/org/incenp/obofoundry/kgcl/owl/OntologyBasedLabelResolverTest.java
@@ -31,6 +31,7 @@
 import org.semanticweb.owlapi.model.OWLOntology;
 import org.semanticweb.owlapi.model.OWLOntologyCreationException;
 import org.semanticweb.owlapi.model.OWLOntologyManager;
+import org.semanticweb.owlapi.vocab.OWLRDFVocabulary;
 
 public class OntologyBasedLabelResolverTest {
 
@@ -74,4 +75,23 @@ void testResolveOBOShorthands() {
         Assertions.assertEquals("http://www.co-ode.org/ontologies/pizza/pizza.owl#hasBase",
                 resolver.resolve("has_base"));
     }
+
+    @Test
+    void testResolveSpecialShorthands() {
+        // Check that "is_a" resolves into rdfs:subClassOf
+        SimpleLabelResolver resolver = new OntologyBasedLabelResolver(ontology);
+        Assertions.assertEquals(OWLRDFVocabulary.RDFS_SUBCLASS_OF.getIRI().toString(), resolver.resolve("is_a"));
+
+        // Unless a class with a "is_a" label exists in the ontology
+        OWLOntologyManager mgr = ontology.getOWLOntologyManager();
+        OWLDataFactory factory = mgr.getOWLDataFactory();
+        IRI dummy = IRI.create("http://www.co-ode.org/ontologies/pizza/pizza.owl#dummy");
+        mgr.addAxiom(ontology, factory.getOWLDeclarationAxiom(factory.getOWLClass(dummy)));
+        mgr.addAxiom(ontology,
+                factory.getOWLAnnotationAssertionAxiom(
+                        factory.getOWLAnnotationProperty(OWLRDFVocabulary.RDFS_LABEL.getIRI()), dummy,
+                        factory.getOWLLiteral("is_a")));
+        resolver = new OntologyBasedLabelResolver(ontology);
+        Assertions.assertEquals(dummy.toString(), resolver.resolve("is_a"));
+    }
 }