diff --git a/samples/main-debug.cc b/samples/main-debug.cc
index d10f5169d..dda796bd9 100644
--- a/samples/main-debug.cc
+++ b/samples/main-debug.cc
@@ -16,7 +16,8 @@ int main (int argc, int argv)
 
   NS3_DEBUG ("other debug output");
 
-  int a = 0;
+  int a;
+  a = 0;
 
   NS3_ASSERT (a == 0);
   NS3_ASSERT_MSG (a == 0, "my msg");