diff --git a/klog.go b/klog.go
index 3462978b..a4290d11 100644
--- a/klog.go
+++ b/klog.go
@@ -873,7 +873,7 @@ func (l *loggingT) output(s severity.Severity, logger *logWriter, buf *buffer.Bu
 		if logger.writeKlogBuffer != nil {
 			logger.writeKlogBuffer(data)
 		} else {
-			if data[len(data)-1] == '\n' {
+			if len(data) > 0 && data[len(data)-1] == '\n' {
 				data = data[:len(data)-1]
 			}
 			// TODO: set 'severity' and caller information as structured log info