diff --git a/cmd/api-errors.go b/cmd/api-errors.go
index eca4d0e09..81c026aff 100644
--- a/cmd/api-errors.go
+++ b/cmd/api-errors.go
@@ -151,6 +151,7 @@ const (
 	ErrBadRequest
 	ErrKeyTooLongError
 	ErrInvalidBucketObjectLockConfiguration
+	ErrObjectLockConfigurationNotFound
 	ErrObjectLockConfigurationNotAllowed
 	ErrNoSuchObjectLockConfiguration
 	ErrObjectLocked
@@ -765,9 +766,14 @@ var errorCodes = errorCodeMap{
 		Description:    "Bucket is missing ObjectLockConfiguration",
 		HTTPStatusCode: http.StatusBadRequest,
 	},
+	ErrObjectLockConfigurationNotFound: {
+		Code:           "ObjectLockConfigurationNotFoundError",
+		Description:    "Object Lock configuration does not exist for this bucket",
+		HTTPStatusCode: http.StatusNotFound,
+	},
 	ErrObjectLockConfigurationNotAllowed: {
 		Code:           "InvalidBucketState",
-		Description:    "Object Lock configuration cannot be enabled on existing buckets.",
+		Description:    "Object Lock configuration cannot be enabled on existing buckets",
 		HTTPStatusCode: http.StatusConflict,
 	},
 	ErrNoSuchObjectLockConfiguration: {
diff --git a/cmd/auth-handler.go b/cmd/auth-handler.go
index 7a7cd8113..1ce94df7d 100644
--- a/cmd/auth-handler.go
+++ b/cmd/auth-handler.go
@@ -591,6 +591,15 @@ func isPutActionAllowed(atype authType, bucketName, objectName string, r *http.R
 		return s3Err
 	}
 
+	// Do not check for PutObjectRetentionAction permission,
+	// if mode and retain until date are not set.
+	// Can happen when bucket has default lock config set
+	if action == iampolicy.PutObjectRetentionAction &&
+		r.Header.Get(xhttp.AmzObjectLockMode) == "" &&
+		r.Header.Get(xhttp.AmzObjectLockRetainUntilDate) == "" {
+		return ErrNone
+	}
+
 	if cred.AccessKey == "" {
 		if globalPolicySys.IsAllowed(policy.Args{
 			AccountName:     cred.AccessKey,
diff --git a/cmd/bucket-handlers.go b/cmd/bucket-handlers.go
index 8210dc0cb..f41892de4 100644
--- a/cmd/bucket-handlers.go
+++ b/cmd/bucket-handlers.go
@@ -1103,7 +1103,7 @@ func (api objectAPIHandlers) GetBucketObjectLockConfigHandler(w http.ResponseWri
 	if err != nil {
 		var aerr APIError
 		if err == errConfigNotFound {
-			aerr = errorCodes.ToAPIErr(ErrMethodNotAllowed)
+			aerr = errorCodes.ToAPIErr(ErrObjectLockConfigurationNotFound)
 		} else {
 			aerr = toAPIError(ctx, err)
 		}
diff --git a/cmd/object-handlers.go b/cmd/object-handlers.go
index 39145e85a..3930a3119 100644
--- a/cmd/object-handlers.go
+++ b/cmd/object-handlers.go
@@ -1029,11 +1029,11 @@ func (api objectAPIHandlers) CopyObjectHandler(w http.ResponseWriter, r *http.Re
 	// apply default bucket configuration/governance headers for dest side.
 	retentionMode, retentionDate, legalHold, s3Err := checkPutObjectLockAllowed(ctx, r, dstBucket, dstObject, getObjectInfo, retPerms, holdPerms)
 	if s3Err == ErrNone && retentionMode.Valid() {
-		srcInfo.UserDefined[xhttp.AmzObjectLockMode] = string(retentionMode)
-		srcInfo.UserDefined[xhttp.AmzObjectLockRetainUntilDate] = retentionDate.UTC().Format(time.RFC3339)
+		srcInfo.UserDefined[strings.ToLower(xhttp.AmzObjectLockMode)] = string(retentionMode)
+		srcInfo.UserDefined[strings.ToLower(xhttp.AmzObjectLockRetainUntilDate)] = retentionDate.UTC().Format(time.RFC3339)
 	}
 	if s3Err == ErrNone && legalHold.Status.Valid() {
-		srcInfo.UserDefined[xhttp.AmzObjectLockLegalHold] = string(legalHold.Status)
+		srcInfo.UserDefined[strings.ToLower(xhttp.AmzObjectLockLegalHold)] = string(legalHold.Status)
 	}
 	if s3Err != ErrNone {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Err), r.URL, guessIsBrowserReq(r))
@@ -2398,11 +2398,7 @@ func (api objectAPIHandlers) CompleteMultipartUploadHandler(w http.ResponseWrite
 		}
 	}
 
-	// Enforce object lock governance in case a competing upload finalized first.
-	retPerms := isPutActionAllowed(getRequestAuthType(r), bucket, object, r, iampolicy.PutObjectRetentionAction)
-	holdPerms := isPutActionAllowed(getRequestAuthType(r), bucket, object, r, iampolicy.PutObjectLegalHoldAction)
-
-	if _, _, _, s3Err := checkPutObjectLockAllowed(ctx, r, bucket, object, objectAPI.GetObjectInfo, retPerms, holdPerms); s3Err != ErrNone {
+	if _, _, _, s3Err := checkPutObjectLockAllowed(ctx, r, bucket, object, objectAPI.GetObjectInfo, ErrNone, ErrNone); s3Err != ErrNone {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(s3Err), r.URL, guessIsBrowserReq(r))
 		return
 	}
diff --git a/cmd/web-handlers.go b/cmd/web-handlers.go
index 8a17ab4bc..1e81d638e 100644
--- a/cmd/web-handlers.go
+++ b/cmd/web-handlers.go
@@ -335,7 +335,7 @@ func (web *webAPIHandlers) ListBuckets(r *http.Request, args *WebGenericArgs, re
 		for _, bucket := range buckets {
 			if globalIAMSys.IsAllowed(iampolicy.Args{
 				AccountName:     claims.AccessKey,
-				Action:          iampolicy.ListBucketAction,
+				Action:          iampolicy.ListAllMyBucketsAction,
 				BucketName:      bucket.Name,
 				ConditionValues: getConditionValues(r, "", claims.AccessKey, claims.Map()),
 				IsOwner:         owner,
diff --git a/pkg/bucket/object/lock/lock.go b/pkg/bucket/object/lock/lock.go
index a5befd778..372680105 100644
--- a/pkg/bucket/object/lock/lock.go
+++ b/pkg/bucket/object/lock/lock.go
@@ -459,10 +459,21 @@ func GetObjectRetentionMeta(meta map[string]string) ObjectRetention {
 	var mode RetMode
 	var retainTill RetentionDate
 
-	if modeStr, ok := meta[strings.ToLower(AmzObjectLockMode)]; ok {
+	var modeStr, tillStr string
+	ok := false
+
+	modeStr, ok = meta[strings.ToLower(AmzObjectLockMode)]
+	if !ok {
+		modeStr, ok = meta[AmzObjectLockMode]
+	}
+	if ok {
 		mode = parseRetMode(modeStr)
 	}
-	if tillStr, ok := meta[strings.ToLower(AmzObjectLockRetainUntilDate)]; ok {
+	tillStr, ok = meta[strings.ToLower(AmzObjectLockRetainUntilDate)]
+	if !ok {
+		tillStr, ok = meta[AmzObjectLockRetainUntilDate]
+	}
+	if ok {
 		if t, e := time.Parse(time.RFC3339, tillStr); e == nil {
 			retainTill = RetentionDate{t.UTC()}
 		}
@@ -473,6 +484,9 @@ func GetObjectRetentionMeta(meta map[string]string) ObjectRetention {
 // GetObjectLegalHoldMeta constructs ObjectLegalHold from metadata
 func GetObjectLegalHoldMeta(meta map[string]string) ObjectLegalHold {
 	holdStr, ok := meta[strings.ToLower(AmzObjectLockLegalHold)]
+	if !ok {
+		holdStr, ok = meta[AmzObjectLockLegalHold]
+	}
 	if ok {
 		return ObjectLegalHold{XMLNS: "http://s3.amazonaws.com/doc/2006-03-01/", Status: parseLegalHoldStatus(holdStr)}
 	}