diff --git a/tools/onlpm.py b/tools/onlpm.py
index 055fb1c1..c5a6404e 100755
--- a/tools/onlpm.py
+++ b/tools/onlpm.py
@@ -209,6 +209,16 @@ class OnlPackage(object):
             p = filename
         else:
             p = os.path.join(self.dir, filename)
+
+        # Globs that result in a single file are allowed:
+        g = glob.glob(p)
+        if len(g) is 0:
+            raise OnlPackageError("'%s' did not match any files." % p)
+        elif len(g) > 1:
+            raise OnlPackageError("'%s' matched too many files %s" % (p, g))
+        else:
+            p = g[0]
+
         logger.debug("package file: %s" % p)
         return p
 
@@ -572,6 +582,7 @@ class OnlPackageGroup(object):
             for p in self.packages:
                 products.append(p.build(dir_=dir_))
 
+
         return products
 
     def clean(self, dir_=None):