diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 59565e8e..4af5ef4c 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "1.6.1"
+  ".": "1.6.2"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 365d6737..7d0f53ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 1.6.2 (2026-04-09)
+
+Full Changelog: [v1.6.1...v1.6.2](https://github.com/OneBusAway/ruby-sdk/compare/v1.6.1...v1.6.2)
+
+### Bug Fixes
+
+* multipart encoding for file arrays ([71fbff0](https://github.com/OneBusAway/ruby-sdk/commit/71fbff0f5e0c29b9af6e7265a31c07f2398aa4df))
+
 ## 1.6.1 (2026-04-01)
 
 Full Changelog: [v1.6.0...v1.6.1](https://github.com/OneBusAway/ruby-sdk/compare/v1.6.0...v1.6.1)
diff --git a/Gemfile.lock b/Gemfile.lock
index da3f4253..bd0b9f48 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -11,7 +11,7 @@ GIT
 PATH
   remote: .
   specs:
-    onebusaway-sdk (1.6.1)
+    onebusaway-sdk (1.6.2)
       cgi
       connection_pool
 
diff --git a/README.md b/README.md
index 2f06e82c..81fd0ab5 100644
--- a/README.md
+++ b/README.md
@@ -17,7 +17,7 @@ To use this gem, install via Bundler by adding the following to your application
 <!-- x-release-please-start-version -->
 
 ```ruby
-gem "onebusaway-sdk", "~> 1.6.1"
+gem "onebusaway-sdk", "~> 1.6.2"
 ```
 
 <!-- x-release-please-end -->
diff --git a/lib/onebusaway_sdk/internal/util.rb b/lib/onebusaway_sdk/internal/util.rb
index 6626d582..88f0f754 100644
--- a/lib/onebusaway_sdk/internal/util.rb
+++ b/lib/onebusaway_sdk/internal/util.rb
@@ -610,6 +610,7 @@ def encode_query_params(query)
         #
         # @return [Array(String, Enumerable<String>)]
         private def encode_multipart_streaming(body)
+          # rubocop:disable Style/CaseEquality
           # RFC 1521 Section 7.2.1 says we should have 70 char maximum for boundary length
           boundary = SecureRandom.urlsafe_base64(46)
 
@@ -619,7 +620,7 @@ def encode_query_params(query)
             in Hash
               body.each do |key, val|
                 case val
-                in Array if val.all? { primitive?(_1) }
+                in Array if val.all? { primitive?(_1) || OnebusawaySDK::Internal::Type::FileInput === _1 }
                   val.each do |v|
                     write_multipart_chunk(y, boundary: boundary, key: key, val: v, closing: closing)
                   end
@@ -635,6 +636,7 @@ def encode_query_params(query)
 
           fused_io = fused_enum(strio) { closing.each(&:call) }
           [boundary, fused_io]
+          # rubocop:enable Style/CaseEquality
         end
 
         # @api private
diff --git a/lib/onebusaway_sdk/version.rb b/lib/onebusaway_sdk/version.rb
index 4fc4a23a..118f693e 100644
--- a/lib/onebusaway_sdk/version.rb
+++ b/lib/onebusaway_sdk/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module OnebusawaySDK
-  VERSION = "1.6.1"
+  VERSION = "1.6.2"
 end