diff --git a/libavutil/timestamp.h b/libavutil/timestamp.h
index f010a7ee38..e082f01b40 100644
--- a/libavutil/timestamp.h
+++ b/libavutil/timestamp.h
@@ -43,7 +43,7 @@
 static inline char *av_ts_make_string(char *buf, int64_t ts)
 {
     if (ts == AV_NOPTS_VALUE) snprintf(buf, AV_TS_MAX_STRING_SIZE, "NOPTS");
-    else                      snprintf(buf, AV_TS_MAX_STRING_SIZE, "%"PRId64, ts);
+    else                      snprintf(buf, AV_TS_MAX_STRING_SIZE, "%" PRId64, ts);
     return buf;
 }