diff --git a/npm_and_yarn/lib/dependabot/npm_and_yarn/update_checker/library_detector.rb b/npm_and_yarn/lib/dependabot/npm_and_yarn/update_checker/library_detector.rb
index 79df070952..22a42c84f1 100644
--- a/npm_and_yarn/lib/dependabot/npm_and_yarn/update_checker/library_detector.rb
+++ b/npm_and_yarn/lib/dependabot/npm_and_yarn/update_checker/library_detector.rb
@@ -42,7 +42,7 @@ def npm_response_matches_package_json?
           @project_npm_response ||= Dependabot::RegistryClient.get(url: url)
           return false unless @project_npm_response.status == 200
 
-          @project_npm_response.body.force_encoding("UTF-8").encode.
+          @project_npm_response.body.dup.force_encoding("UTF-8").encode.
             include?(project_description)
         rescue Excon::Error::Socket, Excon::Error::Timeout, URI::InvalidURIError
           false