diff --git a/.maintainer_mode b/.maintainer_mode
new file mode 100644
index 0000000..e69de29
diff --git a/configure.ac b/configure.ac
index 9a57d93..1f439c8 100644
--- a/configure.ac
+++ b/configure.ac
@@ -41,7 +41,7 @@ AM_INIT_AUTOMAKE([subdir-objects color-tests parallel-tests silent-rules 1.11])
 
 # Activate developer mode when the source is the git repository.
 # Otherwise, it is the source distribution and the developer mode should not be activated.
-AS_IF([test -d ${srcdir}/.git],
+AS_IF([test -d ${srcdir}/.maintainer_mode],
         [enable_maintainer_mode="yes"],
         [enable_maintainer_mode="no"]
 )
diff --git a/org/qmckl_point.org b/org/qmckl_point.org
index 592e7a3..fa30f14 100644
--- a/org/qmckl_point.org
+++ b/org/qmckl_point.org
@@ -285,7 +285,7 @@ qmckl_set_point (qmckl_context context,
 
   if (num <= 0) {
       return qmckl_failwith( context,
-                             QMCKL_INVALID_ARG_4,
+                             QMCKL_INVALID_ARG_3,
                              "qmckl_set_point",
                              "Number of points should be >0.");
   }