diff --git a/du5/program.c b/du5/program.c
index b0dfd35..d5e249c 100644
--- a/du5/program.c
+++ b/du5/program.c
@@ -76,7 +76,7 @@ int main() {
     
     spustac(strom);
 
-    destroy_tree(strom);
+    if (strom != NULL) destroy_tree(strom);
     
     return 0;
 }
\ No newline at end of file