diff --git a/opentelemetry.cabal b/opentelemetry.cabal
--- a/opentelemetry.cabal
+++ b/opentelemetry.cabal
@@ -2,7 +2,7 @@
 name:                opentelemetry
 description:         The OpenTelemetry Haskell Client https://opentelemetry.io
 category:            OpenTelemetry
-version: 0.5.2
+version: 0.5.3
 license-file:        LICENSE
 license:             Apache-2.0
 author:              Dmitry Ivanov
diff --git a/src/OpenTelemetry/Eventlog_Internal.hs b/src/OpenTelemetry/Eventlog_Internal.hs
--- a/src/OpenTelemetry/Eventlog_Internal.hs
+++ b/src/OpenTelemetry/Eventlog_Internal.hs
@@ -84,7 +84,7 @@
 builder_key_value msg (SpanInFlight u) k v =
   let klen = fromIntegral $ BS.length k
       vlen = fromIntegral $ BS.length v
-  in header msg <> word64LE u <> word32LE klen <> word32LE vlen <> byteString k <> byteString v
+   in header msg <> word64LE u <> word32LE klen <> word32LE vlen <> byteString k <> byteString v
 
 {-# INLINE builder_setTag #-}
 builder_setTag :: SpanInFlight -> BS.ByteString -> BS.ByteString -> Builder