diff --git a/pkg/block/fetcher.go b/pkg/block/fetcher.go
index fd0abe3b48..c0e04dbe8e 100644
--- a/pkg/block/fetcher.go
+++ b/pkg/block/fetcher.go
@@ -455,7 +455,7 @@ func (f *BaseFetcher) fetch(ctx context.Context, metrics *fetcherMetrics, filter
 	metrics.submit()
 
 	if len(resp.metaErrs) > 0 {
-		return metas, resp.partial, errors.Wrap(resp.metaErrs, "incomplete view")
+		return metas, resp.partial, errors.Wrap(resp.metaErrs.Err(), "incomplete view")
 	}
 
 	level.Info(f.logger).Log("msg", "successfully synchronized block metadata", "duration", time.Since(start).String(), "cached", len(f.cached), "returned", len(metas), "partial", len(resp.partial))
diff --git a/pkg/compact/compact.go b/pkg/compact/compact.go
index e27478deda..a4345319fa 100644
--- a/pkg/compact/compact.go
+++ b/pkg/compact/compact.go
@@ -543,7 +543,7 @@ func (e HaltError) Error() string {
 // IsHaltError returns true if the base error is a HaltError.
 // If a multierror is passed, any halt error will return true.
 func IsHaltError(err error) bool {
-	if multiErr, ok := errors.Cause(err).(errutil.MultiError); ok {
+	if multiErr, ok := errors.Cause(err).(errutil.NonNilMultiError); ok {
 		for _, err := range multiErr {
 			if _, ok := errors.Cause(err).(HaltError); ok {
 				return true
@@ -576,7 +576,7 @@ func (e RetryError) Error() string {
 // IsRetryError returns true if the base error is a RetryError.
 // If a multierror is passed, all errors must be retriable.
 func IsRetryError(err error) bool {
-	if multiErr, ok := errors.Cause(err).(errutil.MultiError); ok {
+	if multiErr, ok := errors.Cause(err).(errutil.NonNilMultiError); ok {
 		for _, err := range multiErr {
 			if _, ok := errors.Cause(err).(RetryError); !ok {
 				return false
diff --git a/pkg/compact/compact_test.go b/pkg/compact/compact_test.go
index 47423f8812..4f8140e7ce 100644
--- a/pkg/compact/compact_test.go
+++ b/pkg/compact/compact_test.go
@@ -33,11 +33,11 @@ func TestHaltMultiError(t *testing.T) {
 	nonHaltErr := errors.New("not a halt error")
 
 	errs := errutil.MultiError{nonHaltErr}
-	testutil.Assert(t, !IsHaltError(errs), "should not be a halt error")
+	testutil.Assert(t, !IsHaltError(errs.Err()), "should not be a halt error")
 
 	errs.Add(haltErr)
-	testutil.Assert(t, IsHaltError(errs), "if any halt errors are present this should return true")
-	testutil.Assert(t, IsHaltError(errors.Wrap(errs, "wrap")), "halt error with wrap")
+	testutil.Assert(t, IsHaltError(errs.Err()), "if any halt errors are present this should return true")
+	testutil.Assert(t, IsHaltError(errors.Wrap(errs.Err(), "wrap")), "halt error with wrap")
 
 }
 
@@ -46,15 +46,15 @@ func TestRetryMultiError(t *testing.T) {
 	nonRetryErr := errors.New("not a retry error")
 
 	errs := errutil.MultiError{nonRetryErr}
-	testutil.Assert(t, !IsRetryError(errs), "should not be a retry error")
+	testutil.Assert(t, !IsRetryError(errs.Err()), "should not be a retry error")
 
 	errs = errutil.MultiError{retryErr}
-	testutil.Assert(t, IsRetryError(errs), "if all errors are retriable this should return true")
+	testutil.Assert(t, IsRetryError(errs.Err()), "if all errors are retriable this should return true")
 
-	testutil.Assert(t, IsRetryError(errors.Wrap(errs, "wrap")), "retry error with wrap")
+	testutil.Assert(t, IsRetryError(errors.Wrap(errs.Err(), "wrap")), "retry error with wrap")
 
 	errs = errutil.MultiError{nonRetryErr, retryErr}
-	testutil.Assert(t, !IsRetryError(errs), "mixed errors should return false")
+	testutil.Assert(t, !IsRetryError(errs.Err()), "mixed errors should return false")
 }
 
 func TestRetryError(t *testing.T) {
diff --git a/pkg/errutil/multierror.go b/pkg/errutil/multierror.go
index e51bf4554e..aa53706dde 100644
--- a/pkg/errutil/multierror.go
+++ b/pkg/errutil/multierror.go
@@ -12,30 +12,12 @@ import (
 // Errors used to construct it.
 type MultiError []error
 
-// Returns a concatenated string of the contained errors.
-func (es MultiError) Error() string {
-	var buf bytes.Buffer
-
-	if len(es) > 1 {
-		fmt.Fprintf(&buf, "%d errors: ", len(es))
-	}
-
-	for i, err := range es {
-		if i != 0 {
-			buf.WriteString("; ")
-		}
-		buf.WriteString(err.Error())
-	}
-
-	return buf.String()
-}
-
 // Add adds the error to the error list if it is not nil.
 func (es *MultiError) Add(err error) {
 	if err == nil {
 		return
 	}
-	if merr, ok := err.(MultiError); ok {
+	if merr, ok := err.(NonNilMultiError); ok {
 		*es = append(*es, merr...)
 	} else {
 		*es = append(*es, err)
@@ -47,5 +29,25 @@ func (es MultiError) Err() error {
 	if len(es) == 0 {
 		return nil
 	}
-	return es
+	return NonNilMultiError(es)
+}
+
+type NonNilMultiError MultiError
+
+// Returns a concatenated string of the contained errors.
+func (es NonNilMultiError) Error() string {
+	var buf bytes.Buffer
+
+	if len(es) > 1 {
+		fmt.Fprintf(&buf, "%d errors: ", len(es))
+	}
+
+	for i, err := range es {
+		if i != 0 {
+			buf.WriteString("; ")
+		}
+		buf.WriteString(err.Error())
+	}
+
+	return buf.String()
 }
diff --git a/pkg/receive/handler.go b/pkg/receive/handler.go
index 392ecabde1..0337fe495f 100644
--- a/pkg/receive/handler.go
+++ b/pkg/receive/handler.go
@@ -563,7 +563,7 @@ func (h *Handler) fanoutForward(pctx context.Context, tenant string, replicas ma
 			return fctx.Err()
 		case err, more := <-ec:
 			if !more {
-				return errs
+				return errs.Err()
 			}
 			if err == nil {
 				success++
@@ -692,7 +692,7 @@ func determineWriteErrorCause(err error, threshold int) error {
 	}
 
 	unwrappedErr := errors.Cause(err)
-	errs, ok := unwrappedErr.(errutil.MultiError)
+	errs, ok := unwrappedErr.(errutil.NonNilMultiError)
 	if !ok {
 		errs = []error{unwrappedErr}
 	}
diff --git a/pkg/receive/handler_test.go b/pkg/receive/handler_test.go
index 4a06fdd286..70637d49fd 100644
--- a/pkg/receive/handler_test.go
+++ b/pkg/receive/handler_test.go
@@ -44,7 +44,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "nil multierror",
-			err:  errutil.MultiError([]error{}),
+			err:  errutil.NonNilMultiError([]error{}),
 		},
 		{
 			name:      "matching simple",
@@ -54,7 +54,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "non-matching multierror",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				errors.New("foo"),
 				errors.New("bar"),
 			}),
@@ -62,7 +62,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "nested non-matching multierror",
-			err: errors.Wrap(errutil.MultiError([]error{
+			err: errors.Wrap(errutil.NonNilMultiError([]error{
 				errors.New("foo"),
 				errors.New("bar"),
 			}), "baz"),
@@ -71,9 +71,9 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "deep nested non-matching multierror",
-			err: errors.Wrap(errutil.MultiError([]error{
+			err: errors.Wrap(errutil.NonNilMultiError([]error{
 				errors.New("foo"),
-				errutil.MultiError([]error{
+				errutil.NonNilMultiError([]error{
 					errors.New("bar"),
 					errors.New("qux"),
 				}),
@@ -83,7 +83,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "matching multierror",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errors.New("foo"),
 				errors.New("bar"),
@@ -93,7 +93,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "matching but below threshold multierror",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errors.New("foo"),
 				errors.New("bar"),
@@ -103,7 +103,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "matching multierror many",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errConflict,
 				status.Error(codes.AlreadyExists, "conflict"),
@@ -115,7 +115,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "matching multierror many, one above threshold",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errConflict,
 				tsdb.ErrNotReady,
@@ -128,7 +128,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "matching multierror many, both above threshold, conflict have precedence",
-			err: errutil.MultiError([]error{
+			err: errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errConflict,
 				tsdb.ErrNotReady,
@@ -142,7 +142,7 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "nested matching multierror",
-			err: errors.Wrap(errors.Wrap(errutil.MultiError([]error{
+			err: errors.Wrap(errors.Wrap(errutil.NonNilMultiError([]error{
 				storage.ErrOutOfOrderSample,
 				errors.New("foo"),
 				errors.New("bar"),
@@ -152,8 +152,8 @@ func TestDetermineWriteErrorCause(t *testing.T) {
 		},
 		{
 			name: "deep nested matching multierror",
-			err: errors.Wrap(errutil.MultiError([]error{
-				errutil.MultiError([]error{
+			err: errors.Wrap(errutil.NonNilMultiError([]error{
+				errutil.NonNilMultiError([]error{
 					errors.New("qux"),
 					status.Error(codes.AlreadyExists, "conflict"),
 					status.Error(codes.AlreadyExists, "conflict"),