diff --git a/testme.sh b/testme.sh
index ff98d23..c290973 100644
--- a/testme.sh
+++ b/testme.sh
@@ -1,5 +1,12 @@
 #!/bin/bash
 
+if [ $# -lt 3 ]
+then
+  echo "usage is: ${0##*/} <which makefile> <additional defines> <path to math provider>"
+  echo "e.g. \"${0##*/} makefile \"-DUSE_LTM -DLTM_DESC -I/path/to/libtommath\" /path/to/libtommath/libtommath.a\""
+  exit -1
+fi
+
 # date
 echo "date="`date`