diff --git a/py/minimint/mist_interpolator.py b/py/minimint/mist_interpolator.py
index 8679520..f087832 100644
--- a/py/minimint/mist_interpolator.py
+++ b/py/minimint/mist_interpolator.py
@@ -66,7 +66,9 @@ def read_grid(eep_prefix, outp_prefix):
     mask = os.path.join(eep_prefix, '*EEPS', '*eep')
     fs = glob.glob(mask)
     if len(fs) == 0:
-        raise RuntimeError(f'Failed to find eep files {mask}')
+        raise RuntimeError(f'Failed to find eep files {mask}' +
+                           str(os.path.join(eep_prefix, '*')) + '\n' +
+                           str(os.path.join(eep_prefix, '*', '*')))
     tmpfile = utils.tail_head(fs[0], 11, 10)
     tab0 = atpy.Table().read(tmpfile, format='ascii.fast_commented_header')
     os.unlink(tmpfile)