diff --git a/vector/src/Data/Vector/Generic.hs b/vector/src/Data/Vector/Generic.hs
index ec847c20..ebdffe0f 100644
--- a/vector/src/Data/Vector/Generic.hs
+++ b/vector/src/Data/Vector/Generic.hs
@@ -29,7 +29,7 @@ module Data.Vector.Generic (
   length, null,
 
   -- ** Indexing
-  (!), (!?), head, last,
+  (!), (!?), head, vectorToMaybe, last,
   unsafeIndex, unsafeHead, unsafeLast,
 
   -- ** Monadic indexing
@@ -244,10 +244,21 @@ v !? i | i `inRange` length v = case basicUnsafeIndexM v i of Box a -> Just a
 
 
 -- | /O(1)/ First element.
+--
+-- Partial.
+-- Undefined at @fromList [ ]@.
+-- Completion is 'vectorToMaybe'
 head :: Vector v a => v a -> a
 {-# INLINE_FUSED head #-}
 head v = v ! 0
 
+-- | /O(1)/ Just the first element — or nothing when there are none.
+--
+-- Completes 'head'.
+vectorToMaybe :: Vector v a => v a -> Maybe a
+{-# INLINE_FUSED vectorToMaybe #-}
+vectorToMaybe v = v !? 0
+
 -- | /O(1)/ Last element.
 last :: Vector v a => v a -> a
 {-# INLINE_FUSED last #-}
diff --git a/vector/tests/Tests/Vector/Property.hs b/vector/tests/Tests/Vector/Property.hs
index dc8f0b63..c033ece9 100644
--- a/vector/tests/Tests/Vector/Property.hs
+++ b/vector/tests/Tests/Vector/Property.hs
@@ -98,7 +98,7 @@ testPolymorphicFunctions _ = $(testProperties [
         'prop_length, 'prop_null,
 
         -- Indexing
-        'prop_index, 'prop_safeIndex, 'prop_head, 'prop_last,
+        'prop_index, 'prop_safeIndex, 'prop_head, 'prop_vectorToMaybe, 'prop_last,
         'prop_unsafeIndex, 'prop_unsafeHead, 'prop_unsafeLast,
 
         -- Monadic indexing (FIXME)
@@ -241,6 +241,7 @@ testPolymorphicFunctions _ = $(testProperties [
     prop_createT = (\v -> V.createT (T.mapM V.thaw v)) `eq` id
 
     prop_head      :: P (v a -> a) = not . V.null ===> V.head `eq` head
+    prop_vectorToMaybe :: P (v a -> Maybe a) = not . V.null ===> V.vectorToMaybe `eq` (Just . head)
     prop_last      :: P (v a -> a) = not . V.null ===> V.last `eq` last
     prop_index        = \xs ->
                         not (V.null xs) ==>