diff --git a/lib/jars/lock.rb b/lib/jars/lock.rb
index c4fad5e..2eec475 100644
--- a/lib/jars/lock.rb
+++ b/lib/jars/lock.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'jars/maven_exec'
+require 'uri'
 
 module Jars
   class JarDetails < Array
@@ -49,7 +50,8 @@ def path
 
   class Lock
     def initialize(file)
-      @file = file
+      # JRuby treats percent escapes literally in uri:file paths
+      @file = file.start_with?('uri:file:') ? URI::DEFAULT_PARSER.unescape(file) : file
     end
 
     def process(scope)
diff --git a/specs/classpath_spec.rb b/specs/classpath_spec.rb
index a2eee99..adfacbd 100644
--- a/specs/classpath_spec.rb
+++ b/specs/classpath_spec.rb
@@ -3,6 +3,7 @@
 require File.expand_path('setup', File.dirname(__FILE__))
 
 require 'yaml'
+require 'tmpdir'
 
 module Helper
   def self.prepare!(array)
@@ -207,6 +208,20 @@ def self.prepare(array)
     _(Helper.prepare(subject.classpath(:runtime))).must_equal Helper.prepare(lock_expected_runtime)
   end
 
+  it 'processes classloader Jars.lock URLs with spaces in the path' do
+    Dir.mktmpdir do |root|
+      dir = File.join(root, 'jar dependencies')
+      Dir.mkdir(dir)
+      lock = File.join(dir, 'Jars.lock')
+      File.write(lock, "org.slf4j:slf4j-simple:1.6.6:compile:\n")
+      url = "uri:file:#{URI::DEFAULT_PARSER.escape(lock)}"
+
+      _(Jars::Classpath.new(nil, url).classpath).must_equal [
+        File.join(Jars.home, 'org/slf4j/slf4j-simple/1.6.6/slf4j-simple-1.6.6.jar')
+      ]
+    end
+  end
+
   it 'processes Jars.lock and block loading of jars' do
     subject.instance_variable_set(:@deps, jars_no_jline_lock)