diff --git a/Command/Unused.hs b/Command/Unused.hs
index bf98e53bcd..c2179447d0 100644
--- a/Command/Unused.hs
+++ b/Command/Unused.hs
@@ -189,7 +189,12 @@ bloomBitsHashes :: Annex (Int, Int)
 bloomBitsHashes = do
 	capacity <- bloomCapacity
 	accuracy <- bloomAccuracy
-	return $ suggestSizing capacity (1/ fromIntegral accuracy)
+	case safeSuggestSizing capacity (1 / fromIntegral accuracy) of
+		Left e -> do
+			warning $ "bloomfilter " ++ e ++ "; falling back to sane value"
+			-- precaulculated value for 500000 (1/1000)
+			return (8388608,10)
+		Right v -> return v
 
 {- Creates a bloom filter, and runs an action, such as withKeysReferenced,
  - to populate it.
diff --git a/Utility/Bloom.hs b/Utility/Bloom.hs
index e3000de3d7..b0988a8c42 100644
--- a/Utility/Bloom.hs
+++ b/Utility/Bloom.hs
@@ -9,7 +9,7 @@
 
 module Utility.Bloom (
 	Bloom,
-	suggestSizing,
+	safeSuggestSizing,
 	Hashable,
 	cheapHashes,
 	notElemB,
@@ -25,7 +25,7 @@ import qualified Data.BloomFilter as Bloom
 #else
 import qualified Data.BloomFilter as Bloom
 #endif
-import Data.BloomFilter.Easy (suggestSizing, Bloom)
+import Data.BloomFilter.Easy (safeSuggestSizing, Bloom)
 import Data.BloomFilter.Hash (Hashable, cheapHashes)
 import Control.Monad.ST.Safe (ST)
 
diff --git a/debian/changelog b/debian/changelog
index 710f72a34f..c2e0ea5088 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -20,6 +20,8 @@ git-annex (5.20140832) UNRELEASED; urgency=medium
     the repository, rather than just the file's base name. Note that if you're
     relying on such things to keep files separate with WORM, you should really
     be using a better backend.
+  * Rather than crashing when there's a problem with the requested bloomfilter
+    capacity/accuracy, fall back to a reasonable default bloom filter size.
 
  -- Joey Hess <joeyh@debian.org>  Thu, 04 Sep 2014 16:17:22 -0400