diff --git a/aqt/customstudy.py b/aqt/customstudy.py
index e725988f0..5dc08f5be 100644
--- a/aqt/customstudy.py
+++ b/aqt/customstudy.py
@@ -62,6 +62,7 @@ class CustomStudy(QDialog):
             tit = _("New cards in deck over today limit: %s") % plus(newExceeding)
             pre = _("Increase today's new card limit by")
             sval = min(new, self.deck.get('extendNew', 10))
+            smin = -DYN_MAX_SIZE
             smax = newExceeding
         elif idx == RADIO_REV:
             rev = self.mw.col.sched.totalRevForCurrentDeck()
@@ -71,6 +72,7 @@ class CustomStudy(QDialog):
             tit = _("Reviews due in deck over today limit: %s") % plus(revExceeding)
             pre = _("Increase today's review limit by")
             sval = min(rev, self.deck.get('extendRev', 10))
+            smin = -DYN_MAX_SIZE
             smax = revExceeding
         elif idx == RADIO_FORGOT:
             pre = _("Review cards forgotten in last")