diff --git a/gradint-build/src/play.py b/gradint-build/src/play.py
index b2706aff7a04274899fbb1f425b230f07c10a437..9db803b9a074e492250829a8fa38aa301c139bd0 100644
--- a/gradint-build/src/play.py
+++ b/gradint-build/src/play.py
@@ -115,6 +115,7 @@ def digitPrefix(v): # in case we don't have regexp library
     l = []
     for d in list(v):
         if '0' <= d <= '9': l.append(d)
+        else: break
     return intor0(''.join(l))
 
 sox_effect=""