diff --git a/src/unit_test.h b/src/unit_test.h
index 6f67204d..d96c7e72 100644
--- a/src/unit_test.h
+++ b/src/unit_test.h
@@ -15,7 +15,7 @@
 /* Maximum number of command-line arguments.
  * Must be at least as large as the total number of tests
  * to allow specifying all tests individually. */
-#define MAX_ARGS 200
+#define MAX_ARGS 400
 /* Maximum number of parallel jobs */
 #define MAX_SUBPROCESSES 16