diff --git a/src/Type.cc b/src/Type.cc
index b840fa98e3..00b3a5fd7b 100644
--- a/src/Type.cc
+++ b/src/Type.cc
@@ -1691,7 +1691,7 @@ void VectorType::Describe(ODesc* d) const
 	yield_type->Describe(d);
 	}
 
-BroType* base_type(TypeTag tag)
+BroType* base_type_no_ref(TypeTag tag)
 	{
 	static BroType* base_types[NUM_TYPES];
 
@@ -1707,7 +1707,7 @@ BroType* base_type(TypeTag tag)
 		base_types[t]->SetLocationInfo(&l);
 		}
 
-	return base_types[t]->Ref();
+	return base_types[t];
 	}
 
 
diff --git a/src/Type.h b/src/Type.h
index 167e7921ac..f16ed97760 100644
--- a/src/Type.h
+++ b/src/Type.h
@@ -613,7 +613,13 @@ extern OpaqueType* bloomfilter_type;
 extern OpaqueType* x509_opaque_type;
 
 // Returns the BRO basic (non-parameterized) type with the given type.
-extern BroType* base_type(TypeTag tag);
+// The reference count of the type is not increased.
+BroType* base_type_no_ref(TypeTag tag);
+
+// Returns the BRO basic (non-parameterized) type with the given type.
+// The caller assumes responsibility for a reference to the type.
+inline BroType* base_type(TypeTag tag)
+	{ return base_type_no_ref(tag)->Ref(); }
 
 // Returns the BRO basic error type.
 inline BroType* error_type()	{ return base_type(TYPE_ERROR); }
diff --git a/src/Val.cc b/src/Val.cc
index fb7a1ce4ba..5f605a178e 100644
--- a/src/Val.cc
+++ b/src/Val.cc
@@ -1152,7 +1152,7 @@ bool PatternVal::DoUnserialize(UnserialInfo* info)
 	}
 
 ListVal::ListVal(TypeTag t)
-: Val(new TypeList(t == TYPE_ANY ? 0 : base_type(t)))
+: Val(new TypeList(t == TYPE_ANY ? 0 : base_type_no_ref(t)))
 	{
 	tag = t;
 	}