diff --git a/passphrase.nimble b/passphrase.nimble
index a5c790e..df84eb4 100644
--- a/passphrase.nimble
+++ b/passphrase.nimble
@@ -1,6 +1,6 @@
 # Package
 
-version       = "0.3.0"
+version       = "0.3.1"
 author        = "Joseph Montanaro"
 description   = "Passphrase generator and dictionary builder"
 license       = "none"
diff --git a/src/passphrase.nim b/src/passphrase.nim
index 876f3fb..2d73ce0 100644
--- a/src/passphrase.nim
+++ b/src/passphrase.nim
@@ -62,7 +62,7 @@ proc parseInput(): (int, int) =
     try:
       length = parseInt(params[0])
     except ValueError:
-      quit(params[0] & " is not a valid passphrase length.", 1)
+      quit('"' & params[0] & "\" is not a valid passphrase length.", 1)
 
   if params.len > 1:
     try:
@@ -70,7 +70,7 @@ proc parseInput(): (int, int) =
       if dictSize < 100 or dictSize > dict.len:
         quit("Dictionary size must be between 100 and " & $dict.len, 1)
     except ValueError:
-      quit(params[1] & " is not a valid dictionary size.", 1)
+      quit('"' & params[1] & "\" is not a valid dictionary size.", 1)
 
   result = (length, dictSize)