diff --git a/fhirpath/src/main/java/au/csiro/pathling/fhirpath/function/StandardFunctions.java b/fhirpath/src/main/java/au/csiro/pathling/fhirpath/function/StandardFunctions.java
index e35c232c15..f1301dca6f 100644
--- a/fhirpath/src/main/java/au/csiro/pathling/fhirpath/function/StandardFunctions.java
+++ b/fhirpath/src/main/java/au/csiro/pathling/fhirpath/function/StandardFunctions.java
@@ -29,10 +29,6 @@
 @SuppressWarnings("unused")
 public class StandardFunctions {
 
-  public static boolean isTypeSpecifierFunction(@Nonnull final String functionName) {
-    return "ofType".equals(functionName) || "getReferenceKey".equals(functionName);
-  }
-
   // TODO: This should be a string collection with a StringCoercible argument
   @FhirPathFunction
   public static Collection toString(@Nonnull final Collection input) {
diff --git a/fhirpath/src/main/java/au/csiro/pathling/fhirpath/parser/InvocationVisitor.java b/fhirpath/src/main/java/au/csiro/pathling/fhirpath/parser/InvocationVisitor.java
index 4c919addd8..8cfcaa7a60 100644
--- a/fhirpath/src/main/java/au/csiro/pathling/fhirpath/parser/InvocationVisitor.java
+++ b/fhirpath/src/main/java/au/csiro/pathling/fhirpath/parser/InvocationVisitor.java
@@ -17,7 +17,6 @@
 
 package au.csiro.pathling.fhirpath.parser;
 
-import static au.csiro.pathling.fhirpath.function.StandardFunctions.isTypeSpecifierFunction;
 import static java.util.Objects.requireNonNull;
 import static java.util.function.Predicate.not;
 import static java.util.stream.Collectors.toList;
@@ -32,6 +31,10 @@
 import au.csiro.pathling.fhirpath.parser.generated.FhirPathParser.ThisInvocationContext;
 import au.csiro.pathling.fhirpath.parser.generated.FhirPathParser.TotalInvocationContext;
 import au.csiro.pathling.fhirpath.parser.generated.FhirPathVisitor;
+import au.csiro.pathling.fhirpath.path.Paths.EvalFunction;
+import au.csiro.pathling.fhirpath.path.Paths.Resource;
+import au.csiro.pathling.fhirpath.path.Paths.This;
+import au.csiro.pathling.fhirpath.path.Paths.Traversal;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
@@ -40,10 +43,6 @@
 import java.util.stream.Stream;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
-import au.csiro.pathling.fhirpath.path.Paths.EvalFunction;
-import au.csiro.pathling.fhirpath.path.Paths.Resource;
-import au.csiro.pathling.fhirpath.path.Paths.This;
-import au.csiro.pathling.fhirpath.path.Paths.Traversal;
 import org.hl7.fhir.r4.model.Enumerations.ResourceType;
 
 /**
@@ -71,6 +70,10 @@ public InvocationVisitor() {
     this(false);
   }
 
+  private static boolean isTypeSpecifierFunction(@Nonnull final String functionName) {
+    return "ofType".equals(functionName) || "getReferenceKey".equals(functionName);
+  }
+
   /**
    * This method gets called when an element is on the right-hand side of the invocation expression,
    * or when an identifier is referred to as a term (e.g. "Encounter" or "type").