diff --git a/common/lib/dependabot/pull_request_creator/message_builder.rb b/common/lib/dependabot/pull_request_creator/message_builder.rb
index ef3177bfde3..0dd7d7d8ecb 100644
--- a/common/lib/dependabot/pull_request_creator/message_builder.rb
+++ b/common/lib/dependabot/pull_request_creator/message_builder.rb
@@ -85,7 +85,7 @@ def truncate_pr_message(msg)
           msg = (msg[0..trunc_length] + tr_msg)
         end
         # if we used a custom encoding for calculating length, then we need to force back to UTF-8
-        msg.force_encoding(Encoding::UTF_8) unless pr_message_encoding.nil?
+        msg = msg.encode("utf-8", "binary", invalid: :replace, undef: :replace) unless pr_message_encoding.nil?
         msg
       end
 
diff --git a/common/spec/dependabot/pull_request_creator/message_builder_spec.rb b/common/spec/dependabot/pull_request_creator/message_builder_spec.rb
index bd7da9401e0..b7e884ba10e 100644
--- a/common/spec/dependabot/pull_request_creator/message_builder_spec.rb
+++ b/common/spec/dependabot/pull_request_creator/message_builder_spec.rb
@@ -2791,11 +2791,17 @@ def commits_details(base:, head:)
         trunc_msg = (+"...\n\n_Description has been truncated_").force_encoding(encode_utf16)
         trunc_length = pr_message_max_length - trunc_msg.length
         msg = "#{msg[0..trunc_length]}#{trunc_msg}"
-        msg = msg.force_encoding(Encoding::UTF_8)
+        msg = msg.encode("utf-8", "binary", invalid: :replace, undef: :replace)
 
         message_builder.pr_message_max_length = pr_message_max_length
         message_builder.pr_message_encoding = encode_utf16
         expect(message_builder.truncate_pr_message(message)).to eq(msg)
+
+        # ensure we can work convert to JSON (uses UTF-8 by default)
+        # this matches what happens in the azure client when creating a pull request
+        expect({ description: msg }.to_json)
+          .to start_with("{\"description\":\"")
+          .and end_with("\\n\\n_Description has been truncated_\"}")
       end
     end