diff --git a/cc/google/fhir/fhir_path/fhir_path.cc b/cc/google/fhir/fhir_path/fhir_path.cc
index c58dd479a..11be531a1 100644
--- a/cc/google/fhir/fhir_path/fhir_path.cc
+++ b/cc/google/fhir/fhir_path/fhir_path.cc
@@ -2625,6 +2625,9 @@ class ChildrenFunction : public ZeroParameterFunctionNode {
 
     for (const WorkspaceMessage& child : child_results) {
       const Descriptor* descriptor = child.Message()->GetDescriptor();
+      if (IsPrimitive(descriptor)) {
+        continue;
+      }
       for (int i = 0; i < descriptor->field_count(); i++) {
         std::vector<const Message*> messages;
         FHIR_RETURN_IF_ERROR(
diff --git a/cc/google/fhir/fhir_path/fhir_path_test.cc b/cc/google/fhir/fhir_path/fhir_path_test.cc
index dcbfa2b8b..81af787fa 100644
--- a/cc/google/fhir/fhir_path/fhir_path_test.cc
+++ b/cc/google/fhir/fhir_path/fhir_path_test.cc
@@ -738,6 +738,8 @@ TYPED_TEST(FhirPathTest, TestFunctionChildren) {
       UnorderedElementsAreArray(
           {EqualsProto(structure_definition.snapshot().element(0)),
            EqualsProto(structure_definition.differential().element(0))}));
+
+  EXPECT_THAT(TestFixture::Evaluate("(1 | 2).children()"), EvalsToEmpty());
 }
 
 TYPED_TEST(FhirPathTest, TestFunctionDescendants) {
@@ -763,6 +765,9 @@ TYPED_TEST(FhirPathTest, TestFunctionDescendants) {
            EqualsProto(structure_definition.differential().element(0)),
            EqualsProto(
                structure_definition.differential().element(0).label())}));
+
+  EXPECT_THAT(TestFixture::Evaluate("('foo' | 'bar').descendants()"),
+              EvalsToEmpty());
 }
 
 TYPED_TEST(FhirPathTest, TestFunctionDescendantsOnEmptyCollection) {