diff --git a/examples/vertical_EAS.cpp b/examples/vertical_EAS.cpp
index 58d65a520b7bad1763198936ef314d5c7b392b0a..9f816ce19975a7be024ec08bfd4a8f82308e894f 100644
--- a/examples/vertical_EAS.cpp
+++ b/examples/vertical_EAS.cpp
@@ -103,7 +103,7 @@ int main(int argc, char** argv) {
 
   CORSIKA_LOG_INFO("vertical_EAS");
 
-  if (argc < 4) {
+  if (argc < 5) {
     std::cerr << "usage: vertical_EAS <A> <Z> <energy/GeV> [seed] \n"
                  "       if A=0, Z is interpreted as PDG code \n"
                  "       if no seed is given, a random seed is chosen \n"