diff --git a/ethercat.c b/ethercat.c
index 0c38366..4cbbcc8 100644
--- a/ethercat.c
+++ b/ethercat.c
@@ -58,6 +58,7 @@ int main(int argc, char** argv) {
   stdin_dup = dup(fileno(stdin));
   if (stdin_dup == -1) {
     fprintf(stderr, "Failed to dup() stdin: %s\n", strerror(errno));
+    return EXIT_RUNTIME;
   }
 
   if (freopen(NULL, "wb", stdout) == NULL) {