diff --git a/cmds/atrace/atrace.cpp b/cmds/atrace/atrace.cpp
index a6cde79..965a78e 100644
--- a/cmds/atrace/atrace.cpp
+++ b/cmds/atrace/atrace.cpp
@@ -1239,7 +1239,7 @@
             fflush(stdout);
             int outFd = STDOUT_FILENO;
             if (g_outputFile) {
-                outFd = open(g_outputFile, O_WRONLY | O_CREAT, 0644);
+                outFd = open(g_outputFile, O_WRONLY | O_CREAT | O_TRUNC, 0644);
             }
             if (outFd == -1) {
                 printf("Failed to open '%s', err=%d", g_outputFile, errno);