diff --git a/serokell-util.cabal b/serokell-util.cabal
--- a/serokell-util.cabal
+++ b/serokell-util.cabal
@@ -1,5 +1,5 @@
 name:                serokell-util
-version:             0.7.0
+version:             0.8.0
 synopsis:            General-purpose functions by Serokell
 homepage:            https://github.com/serokell/serokell-util
 license:             MIT
diff --git a/src/Serokell/Util/Verify.hs b/src/Serokell/Util/Verify.hs
--- a/src/Serokell/Util/Verify.hs
+++ b/src/Serokell/Util/Verify.hs
@@ -23,6 +23,7 @@
 import Universum
 
 import Control.Monad.Except (MonadError, throwError)
+import Fmt (fmt)
 
 import Serokell.Util.Text (listBuilder)
 
@@ -69,15 +70,15 @@
 
 -- | Format VerificationRes in a pretty way using all errors messages
 -- for VerFailure.
-verResFullF :: VerificationRes -> B.Builder
+verResFullF :: VerificationRes -> Text
 verResFullF VerSuccess          = "success"
-verResFullF (VerFailure errors) = buildVerResImpl errors
+verResFullF (VerFailure errors) = fmt $ buildVerResImpl errors
 
 -- | Format VerificationRes in a pretty way using only first message
 -- for VerFailure.
-verResSingleF :: VerificationRes -> B.Builder
+verResSingleF :: VerificationRes -> Text
 verResSingleF VerSuccess          = "success"
-verResSingleF (VerFailure errors) = buildVerResImpl $ one $ head errors
+verResSingleF (VerFailure errors) = fmt $ buildVerResImpl $ one $ head errors
 
 buildVerResImpl :: NonEmpty Text -> B.Builder
 buildVerResImpl errors =
@@ -86,11 +87,11 @@
 -- These two functions can have more general type.
 
 -- | Pretty printer for errors from VerFailure, all errors are printed.
-formatAllErrors :: NonEmpty Text -> B.Builder
+formatAllErrors :: NonEmpty Text -> Text
 formatAllErrors = verResFullF . VerFailure
 
 -- | Pretty printer for errors from VerFailure, only first error is printed.
-formatFirstError :: NonEmpty Text -> B.Builder
+formatFirstError :: NonEmpty Text -> Text
 formatFirstError = verResSingleF . VerFailure
 
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