diff --git a/test/default/cmptest.h b/test/default/cmptest.h
index 477abcbd..ae84e43e 100644
--- a/test/default/cmptest.h
+++ b/test/default/cmptest.h
@@ -6,6 +6,10 @@
 
 #include "sodium.h"
 
+#ifndef TEST_SRCDIR
+# define TEST_SRCDIR "."
+#endif
+
 #define TEST_NAME_RES TEST_NAME ".res"
 #define TEST_NAME_OUT TEST_SRCDIR "/" TEST_NAME ".exp"