diff --git a/Data/Array/Base.hs b/Data/Array/Base.hs
index f009f4b985f202022571955e926a566bae2c11dd..3b843d652a148289c4b0dccbfddc5f87ca6cdfbf 100644
--- a/Data/Array/Base.hs
+++ b/Data/Array/Base.hs
@@ -905,6 +905,15 @@ newListArray (l,u) es = do
     fillFromList 0 es
     return marr
 
+-- | Constructs a mutable array using a generator function.
+-- It invokes the generator function in ascending order of the indices.
+newGenArray :: (MArray a e m, Ix i) => (i,i) -> (i -> m e) -> m (a i e)
+newGenArray (l,u) f = do
+    marr <- newArray_ (l,u)
+    let n = safeRangeSize (l,u)
+    sequence_ [ f i >>= unsafeWrite marr (safeIndex (l,u) n i) | i <- range (l,u)]
+    return marr
+
 {-# INLINE readArray #-}
 -- | Read an element from a mutable array
 readArray :: (MArray a e m, Ix i) => a i e -> i -> m e
diff --git a/Data/Array/MArray.hs b/Data/Array/MArray.hs
index 7f0f10541fad344ae9b95f6ae9db7badea9d971b..c7923da02f88fc1193cceaae9aa646519c846805 100644
--- a/Data/Array/MArray.hs
+++ b/Data/Array/MArray.hs
@@ -27,6 +27,7 @@ module Data.Array.MArray (
     newArray,     -- :: (MArray a e m, Ix i) => (i,i) -> e -> m (a i e)
     newArray_,    -- :: (MArray a e m, Ix i) => (i,i) -> m (a i e)
     newListArray, -- :: (MArray a e m, Ix i) => (i,i) -> [e] -> m (a i e)
+    newGenArray,  -- :: (MArray a e m, Ix i) => (i,i) -> (i -> m e) -> m (a i e)
 
     -- * Reading and writing mutable arrays
     readArray,    -- :: (MArray a e m, Ix i) => a i e -> i -> m e
diff --git a/Data/Array/MArray/Safe.hs b/Data/Array/MArray/Safe.hs
index fcbf768c64fe15b20a295717eb1132c91c8a634f..be7a62e82e7ea5dccb7b612725b16eadd8320de5 100644
--- a/Data/Array/MArray/Safe.hs
+++ b/Data/Array/MArray/Safe.hs
@@ -29,6 +29,7 @@ module Data.Array.MArray.Safe (
     newArray,     -- :: (MArray a e m, Ix i) => (i,i) -> e -> m (a i e)
     newArray_,    -- :: (MArray a e m, Ix i) => (i,i) -> m (a i e)
     newListArray, -- :: (MArray a e m, Ix i) => (i,i) -> [e] -> m (a i e)
+    newGenArray,  -- :: (MArray a e m, Ix i) => (i,i) -> (i -> m e) -> m (a i e)
 
     -- * Reading and writing mutable arrays
     readArray,    -- :: (MArray a e m, Ix i) => a i e -> i -> m e
diff --git a/changelog.md b/changelog.md
index 61ca97499e90638bd58df7aff86e6a24ee0170da..fdbaf7d1085e9849a482659a11dadff43f5bec3a 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,7 +2,7 @@
 
 ## 0.5.5.0  *UNRELEASED*
 
-* add the `genArray` function
+* add the `genArray` and `newGenArray` function
 
 ## 0.5.4.0  *July 2019*