diff --git a/proto/google/fhir/proto/r4/fhirproto.proto b/proto/google/fhir/proto/r4/fhirproto.proto
index 5db199040..d31356199 100644
--- a/proto/google/fhir/proto/r4/fhirproto.proto
+++ b/proto/google/fhir/proto/r4/fhirproto.proto
@@ -127,9 +127,7 @@ message ValidationOutcome {
       [(.google.fhir.proto.validation_requirement) = REQUIRED_BY_FHIR];
 
   // The FHIR resource this Validation is for.
-  core.Reference subject = 11 [
-    (.google.fhir.proto.validation_requirement) = REQUIRED_BY_FHIR,
-    (.google.fhir.proto.fhir_inlined_extension_url) =
-        "https://g.co/fhir/medicalrecords/OperationOutcomeSubject"
-  ];
+  core.Reference subject = 11
+      [(.google.fhir.proto.fhir_inlined_extension_url) =
+           "https://g.co/fhir/medicalrecords/OperationOutcomeSubject"];
 }
diff --git a/spec/google/fhirproto.prototxt b/spec/google/fhirproto.prototxt
index 6fb4b82ad..1013fd07e 100644
--- a/spec/google/fhirproto.prototxt
+++ b/spec/google/fhirproto.prototxt
@@ -9,7 +9,6 @@ profile {
     element_data {
       name: "subject"
       description: "The FHIR resource this Validation is for."
-      size_restriction: REQUIRED
     }
     url: "https://g.co/fhir/medicalrecords/OperationOutcomeSubject"
   }
diff --git a/spec/google/r4/google.json b/spec/google/r4/google.json
index 9da397ff7..1c9e13d6a 100755
--- a/spec/google/r4/google.json
+++ b/spec/google/r4/google.json
@@ -10,7 +10,7 @@
         "name": "ValidationOutcome",
         "title": "ValidationOutcome",
         "status": "draft",
-        "date": "2021-08-27",
+        "date": "2021-08-31",
         "publisher": "Google LLC",
         "contact": [
           {
@@ -909,7 +909,7 @@
               "sliceName": "subject",
               "short": "The FHIR resource this Validation is for.",
               "definition": "The FHIR resource this Validation is for.",
-              "min": 1,
+              "min": 0,
               "max": "1",
               "base": {
                 "path": "Extension",
@@ -967,7 +967,6 @@
               "sliceName": "subject",
               "short": "The FHIR resource this Validation is for.",
               "definition": "The FHIR resource this Validation is for.",
-              "min": 1,
               "max": "1",
               "type": [
                 {