diff --git a/util/multierr/multierr.go b/util/multierr/multierr.go
index 83a5cb17f..b4ae0afe5 100644
--- a/util/multierr/multierr.go
+++ b/util/multierr/multierr.go
@@ -53,7 +53,31 @@ func (e Error) Unwrap() []error {
 // If the resulting slice has length 1, New returns that error.
 // If the resulting slice has length > 1, New returns that slice as an Error.
 func New(errs ...error) error {
-	dst := make([]error, 0, len(errs))
+	// First count the number of errors to avoid allocating.
+	var n int
+	var errFirst error
+	for _, e := range errs {
+		switch e := e.(type) {
+		case nil:
+			continue
+		case Error:
+			n += len(e.errs)
+			if errFirst == nil && len(e.errs) > 0 {
+				errFirst = e.errs[0]
+			}
+		default:
+			n++
+			if errFirst == nil {
+				errFirst = e
+			}
+		}
+	}
+	if n <= 1 {
+		return errFirst // nil if n == 0
+	}
+
+	// More than one error, allocate slice and construct the multi-error.
+	dst := make([]error, 0, n)
 	for _, e := range errs {
 		switch e := e.(type) {
 		case nil:
@@ -64,18 +88,6 @@ func New(errs ...error) error {
 			dst = append(dst, e)
 		}
 	}
-	// dst has been filtered and splatted.
-	switch len(dst) {
-	case 0:
-		return nil
-	case 1:
-		return dst[0]
-	}
-	// Zero any remaining elements of dst left over from errs, for GC.
-	tail := dst[len(dst):cap(dst)]
-	for i := range tail {
-		tail[i] = nil
-	}
 	return Error{errs: dst}
 }
 
diff --git a/util/multierr/multierr_test.go b/util/multierr/multierr_test.go
index f8cb729ba..28b4efdb9 100644
--- a/util/multierr/multierr_test.go
+++ b/util/multierr/multierr_test.go
@@ -7,6 +7,7 @@ package multierr_test
 import (
 	"errors"
 	"fmt"
+	"io"
 	"testing"
 
 	qt "github.com/frankban/quicktest"
@@ -106,3 +107,20 @@ func TestRange(t *testing.T) {
 		return x.Error() == y.Error()
 	})), want)
 }
+
+var sink error
+
+func BenchmarkEmpty(b *testing.B) {
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		sink = multierr.New(nil, nil, nil, multierr.Error{})
+	}
+}
+
+func BenchmarkNonEmpty(b *testing.B) {
+	merr := multierr.New(io.ErrShortBuffer, io.ErrNoProgress)
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		sink = multierr.New(io.ErrUnexpectedEOF, merr, io.ErrClosedPipe)
+	}
+}