diff --git a/LICENCE b/LICENCE
deleted file mode 100644
--- a/LICENCE
+++ /dev/null
@@ -1,32 +0,0 @@
-Opinionated Haskell Interoperability
-
-Copyright © 2018-2019 Operational Dynamics Consulting, Pty Ltd and Others
-All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions
-are met:
-
-    1. Redistributions of source code must retain the above copyright
-       notice, this list of conditions and the following disclaimer.
-
-    2. Redistributions in binary form must reproduce the above
-       copyright notice, this list of conditions and the following
-       disclaimer in the documentation and/or other materials provided
-       with the distribution.
-      
-    3. Neither the name of the project nor the names of its contributors
-       may be used to endorse or promote products derived from this 
-       software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,32 @@
+Opinionated Haskell Interoperability
+
+Copyright © 2018-2019 Operational Dynamics Consulting, Pty Ltd and Others
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above
+       copyright notice, this list of conditions and the following
+       disclaimer in the documentation and/or other materials provided
+       with the distribution.
+      
+    3. Neither the name of the project nor the names of its contributors
+       may be used to endorse or promote products derived from this 
+       software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/core-data.cabal b/core-data.cabal
--- a/core-data.cabal
+++ b/core-data.cabal
@@ -1,8 +1,8 @@
 cabal-version: 1.12
 name: core-data
-version: 0.2.0.0
+version: 0.2.1.0
 license: BSD3
-license-file: LICENCE
+license-file: LICENSE
 copyright: © 2018-2019 Operational Dynamics Consulting Pty Ltd, and Others
 maintainer: Andrew Cowie <andrew@operationaldynamics.com>
 author: Andrew Cowie <andrew@operationaldynamics.com>
@@ -37,13 +37,13 @@
     default-language: Haskell2010
     ghc-options: -Wall -Wwarn -fwarn-tabs
     build-depends:
-        aeson >=1.4.2.0 && <1.5,
+        aeson >=1.4.5.0 && <1.5,
         base >=4.11 && <5,
         bytestring >=0.10.8.2 && <0.11,
         containers >=0.6.0.1 && <0.7,
-        core-text >=0.2.0.0 && <0.3,
+        core-text >=0.2.2 && <0.3,
         hashable >=1.2.7.0 && <1.3,
-        prettyprinter >=1.2.1 && <1.3,
+        prettyprinter >=1.2.1.1 && <1.3,
         prettyprinter-ansi-terminal >=1.1.1.2 && <1.2,
         scientific >=0.3.6.2 && <0.4,
         text >=1.2.3.1 && <1.3,
diff --git a/lib/Core/Data/Structures.hs b/lib/Core/Data/Structures.hs
--- a/lib/Core/Data/Structures.hs
+++ b/lib/Core/Data/Structures.hs
@@ -38,6 +38,7 @@
 )
 where
 
+import qualified Data.ByteString as B (ByteString)
 import Data.Foldable (Foldable(..))
 import Data.Hashable (Hashable)
 import qualified Data.HashMap.Strict as HashMap
@@ -100,6 +101,7 @@
 instance Key U.Text
 instance Key Char
 instance Key Int
+instance Key B.ByteString
 
 instance Foldable (Map κ) where
     foldr f start (Map u) = HashMap.foldr f start u