diff --git a/README.md b/README.md
index 36e20a53..a6fb6fcd 100644
--- a/README.md
+++ b/README.md
@@ -898,7 +898,7 @@ Prepared statements will automatically be created for any queries where it can b
 
 ## Custom Types
 
-You can add ergonomic support for custom types, or simply use `sql.typed(value, type)` inline, where type is the PostgreSQL `oid` for the type and the correctly serialized string. _(`oid` values for types can be found in the `pg_catalog.pg_types` table.)_
+You can add ergonomic support for custom types, or simply use `sql.typed(value, type)` inline, where type is the PostgreSQL `oid` for the type and the correctly serialized string. _(`oid` values for types can be found in the `pg_catalog.pg_type` table.)_
 
 Adding Query helpers is the cleanest approach which can be done like this:
 
diff --git a/src/types.js b/src/types.js
index 93ddaa29..521b2d95 100644
--- a/src/types.js
+++ b/src/types.js
@@ -243,7 +243,7 @@ export const arraySerializer = function arraySerializer(xs, serializer) {
   if (Array.isArray(first) && !first.type)
     return '{' + xs.map(x => arraySerializer(x, serializer)).join(',') + '}'
 
-  return '{' + xs.map(x =>
+  return '{' + xs.map(x => x == null ? 'null' :
     '"' + arrayEscape(serializer ? serializer(x.type ? x.value : x) : '' + x) + '"'
   ).join(',') + '}'
 }