diff --git a/src/Data.Proquint.purs b/src/Data.Proquint.purs
index 03bada2..ca5b94b 100644
--- a/src/Data.Proquint.purs
+++ b/src/Data.Proquint.purs
@@ -23,9 +23,8 @@ import Data.Show.Generic (genericShow)
 import Data.String as String
 import Data.Traversable (for, traverse)
 import Data.Tuple.Nested ((/\))
-import Effect (Effect)
 import Effect.Unsafe (unsafePerformEffect)
-import Node.Buffer (Buffer, BufferValueType(..))
+import Node.Buffer (BufferValueType(..))
 import Node.Buffer as Buffer
 import Node.Buffer.Immutable (ImmutableBuffer)
 import Node.Buffer.Immutable as Buffer.Immutable
@@ -181,6 +180,9 @@ derive instance Eq Segment
 instance Show Segment where
   show = genericShow
 
+segmentZero :: Segment
+segmentZero = Segment ConB VoA ConB VoA ConB
+
 segmentBits :: Segment -> Int
 segmentBits (Segment a b c d e) =
   let
@@ -231,6 +233,16 @@ derive instance Eq Proquint
 instance Show Proquint where
   show = genericShow
 
+pad :: Int -> Proquint -> Proquint
+pad n pq@(Proquint segs) =
+  let
+    len = Array.length segs
+  in
+    if len < n then
+      Proquint $ Array.replicate (n - len) segmentZero <> segs
+    else
+      pq
+
 toString :: Proquint -> String
 toString (Proquint segments) = intercalate "-" $ map segmentToString segments
 
@@ -246,12 +258,12 @@ fromInt n = fromBits $ unsafePerformEffect do
 
 toInt :: Proquint -> Maybe Int
 toInt pq@(Proquint segs)
-  | Array.length segs <= 2 = Int.fromNumber $ Buffer.Immutable.read UInt32BE 0 $ toBits pq
+  | Array.length segs <= 2 = Int.fromNumber $ Buffer.Immutable.read UInt32BE 0 $ toBits $ pad 2 pq
   | otherwise = Nothing
 
 toBigInt :: Proquint -> Maybe BigInt
 toBigInt pq@(Proquint segs)
-  | Array.length segs <= 4 = Just $ Buffer.Immutable.BigInt.readBigUInt64BE 0 $ toBits pq
+  | Array.length segs <= 4 = Just $ Buffer.Immutable.BigInt.readBigUInt64BE 0 $ toBits $ pad 4 pq
   | otherwise = Nothing
 
 fromBigInt :: BigInt -> Proquint