diff --git a/lib/bootsnap/load_path_cache/cache.rb b/lib/bootsnap/load_path_cache/cache.rb
index c1e1dc7b..a1eab1bb 100644
--- a/lib/bootsnap/load_path_cache/cache.rb
+++ b/lib/bootsnap/load_path_cache/cache.rb
@@ -9,7 +9,7 @@ def initialize(store, path_obj, development_mode: false)
         @development_mode = development_mode
         @store = store
         @mutex = defined?(::Mutex) ? ::Mutex.new : ::Thread::Mutex.new # TODO: Remove once Ruby 2.2 support is dropped.
-        @path_obj = path_obj.map { |f| File.exist?(f) ? File.realpath(f) : f }
+        @path_obj = path_obj.map! { |f| File.exist?(f) ? File.realpath(f) : f }
         @has_relative_paths = nil
         reinitialize
       end