diff --git a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
index a948ba214..2badb07ec 100644
--- a/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
+++ b/org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java
@@ -7459,7 +7459,8 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   public ValidationResult checkCodeOnServer(NodeStack stack, ValueSet valueset, CodeableConcept cc) throws CheckCodeOnServerException {
     codingObserver.seeCode(stack, cc);
     try {
-      return checkForInactive(filterOutSpecials(stack.getLiteralPath(), valueset, context.validateCode(baseOptions.withLanguage(stack.getWorkingLang()), cc, valueset)), cc);
+      String workingLang = stack.getWorkingLang() != null ? stack.getWorkingLang() : context.getLocale().toString();
+      return checkForInactive(filterOutSpecials(stack.getLiteralPath(), valueset, context.validateCode(baseOptions.withLanguage(workingLang), cc, valueset)), cc);
     } catch (Exception e) {
       throw new CheckCodeOnServerException(e);
     }
diff --git a/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTest.java b/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTest.java
deleted file mode 100644
index 402b9b1aa..000000000
--- a/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTest.java
+++ /dev/null
@@ -1,7 +0,0 @@
-package org.hl7.fhir.validation.instance;
-
-class InstanceValidatorTest {
-
-
-
-}
\ No newline at end of file
diff --git a/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTests.java b/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTests.java
new file mode 100644
index 000000000..30294121b
--- /dev/null
+++ b/org.hl7.fhir.validation/src/test/java/org/hl7/fhir/validation/instance/InstanceValidatorTests.java
@@ -0,0 +1,57 @@
+package org.hl7.fhir.validation.instance;
+
+import org.hl7.fhir.r5.terminologies.utilities.ValidationResult;
+import org.hl7.fhir.utilities.validation.ValidationMessage;
+import org.hl7.fhir.utilities.validation.ValidationOptions;
+import org.hl7.fhir.r5.context.IWorkerContext;
+import org.hl7.fhir.r5.model.CodeableConcept;
+import org.hl7.fhir.r5.model.ValueSet;
+import org.hl7.fhir.validation.instance.utils.NodeStack;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+import org.mockito.ArgumentCaptor;
+
+import java.util.Collections;
+import java.util.Locale;
+
+import static org.junit.Assert.assertEquals;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.*;
+
+class InstanceValidatorTests {
+
+  @Test
+  public void testCheckCodeOnServerNoStackLocale() throws InstanceValidator.CheckCodeOnServerException {
+      NodeStack stack =mock(NodeStack.class);
+      testCheckCodeOnServer(stack, "ko_KR");
+  }
+
+  @Test
+  public void testCheckCodeOnServerStackLocale() throws InstanceValidator.CheckCodeOnServerException {
+      NodeStack stack =mock(NodeStack.class);
+      when(stack.getWorkingLang()).thenReturn("fr-CA");
+      testCheckCodeOnServer(stack, "fr-CA");
+  }
+
+  private void testCheckCodeOnServer(NodeStack stack, String expectedLocale) throws InstanceValidator.CheckCodeOnServerException {
+    IWorkerContext context = mock(IWorkerContext.class);
+    when(context.getLocale()).thenReturn(Locale.KOREA);
+    when(context.getVersion()).thenReturn("5.0.1");
+    InstanceValidator instanceValidator = new InstanceValidator(context, null, null);
+
+
+    when(context.validateCode((ValidationOptions) any(ValidationOptions.class), (CodeableConcept) any(CodeableConcept.class), (ValueSet)any(ValueSet.class))).thenReturn(new ValidationResult(ValidationMessage.IssueSeverity.NULL, "Blah!", Collections.emptyList()));
+
+    CodeableConcept codeableConcept = mock(CodeableConcept.class);
+    ValueSet valueSet = mock(ValueSet.class);
+    instanceValidator.checkCodeOnServer(stack, valueSet, codeableConcept);
+
+    ArgumentCaptor<ValidationOptions> validationOptionsArgumentCaptor = ArgumentCaptor.forClass(ValidationOptions.class);
+    verify(context).validateCode(validationOptionsArgumentCaptor.capture(), eq(codeableConcept), eq(valueSet));
+
+    ValidationOptions options = validationOptionsArgumentCaptor.getValue();
+
+    Assertions.assertEquals(expectedLocale, options.getLanguages().getSource());
+  }
+
+}
\ No newline at end of file