diff --git a/fhir-server/src/test/java/au/csiro/pathling/extract/ExtractQueryTest.java b/fhir-server/src/test/java/au/csiro/pathling/extract/ExtractQueryTest.java
index e654d1def5..22f1e1f81b 100644
--- a/fhir-server/src/test/java/au/csiro/pathling/extract/ExtractQueryTest.java
+++ b/fhir-server/src/test/java/au/csiro/pathling/extract/ExtractQueryTest.java
@@ -332,6 +332,22 @@ void multipleNonSingularColumnsWithDifferentTypes() {
             "responses/ExtractQueryTest/multipleNonSingularColumnsWithDifferentTypes.csv");
   }
 
+  @Test
+  void issue1770() {
+    subjectResource = ResourceType.OBSERVATION;
+    mockResource(subjectResource);
+
+    final ExtractRequest request = new ExtractRequestBuilder(subjectResource)
+        .withColumn("id")
+        .withColumn("valueQuantity.value")
+        .build();
+
+    final Dataset<Row> result = executor.buildQuery(request);
+    assertThat(result)
+        .debugAllRows();
+    result.printSchema();
+  }
+
   @Test
   void emptyColumn() {
     subjectResource = ResourceType.PATIENT;
diff --git a/lib/python/tests/test_query.py b/lib/python/tests/test_query.py
index 6a1f5440de..e03f1bd4c6 100644
--- a/lib/python/tests/test_query.py
+++ b/lib/python/tests/test_query.py
@@ -28,6 +28,13 @@ def test_data_source(pathling_ctx, test_data_dir):
     return pathling_ctx.read.ndjson(os.path.join(test_data_dir, "ndjson"))
 
 
+@fixture(scope="module")
+def test_bundles_data_source(pathling_ctx, test_data_dir):
+    return pathling_ctx.read.bundles(
+        os.path.join(test_data_dir, "bundles"), resource_types=["Observation"]
+    )
+
+
 def test_extract(test_data_source):
     result = test_data_source.extract(
         "Patient",
@@ -85,6 +92,27 @@ def test_extract_no_filters(test_data_source):
     )
 
 
+def test_extract_issue_1770(test_bundles_data_source):
+    result = test_bundles_data_source.extract(
+        "Observation",
+        columns=[
+            Expression("id", "Identifier"),
+            Expression("valueQuantity.value", "Value_Quantity"),
+        ],
+    )
+
+    # noinspection PyPep8Naming
+    ExtractRow = Row("Identifier", "Value_Quantity")
+
+    assert_result(
+        [
+            ExtractRow("e1f0e0c0-0f2e-4e1f-8e1a-0e1f0e0c0f2e", 0.0),
+            ExtractRow("e1f0e0c0-0f2e-4e1f-8e1a-0e1f0e0c0f2e", 0.0),
+        ],
+        result.orderBy("Identifier", "Value_Quantity").limit(2).collect(),
+    )
+
+
 def test_aggregate(test_data_source):
     agg_result = test_data_source.aggregate(
         "Patient",