diff --git a/cmds/dumpstate/dumpstate.h b/cmds/dumpstate/dumpstate.h
index 4769974..4dde125 100644
--- a/cmds/dumpstate/dumpstate.h
+++ b/cmds/dumpstate/dumpstate.h
@@ -218,7 +218,7 @@
  */
 class DurationReporter {
 public:
-    DurationReporter(const char *title);
+    explicit DurationReporter(const char *title);
     DurationReporter(const char *title, FILE* out);
 
     ~DurationReporter();