diff --git a/shard.yml b/shard.yml
index 7ed0120..d97b9d5 100644
--- a/shard.yml
+++ b/shard.yml
@@ -6,7 +6,7 @@ authors:
 
 license: MIT
 
-crystal: 0.24.2
+crystal: ">= 0.24.2, < 2.0.0"
 
 dependencies:
   stdio:
diff --git a/src/have_files.cr b/src/have_files.cr
index 22f7ef6..02f7bf9 100644
--- a/src/have_files.cr
+++ b/src/have_files.cr
@@ -28,7 +28,7 @@ module HaveFiles
           end
         end
       end
-      Dir.rmdir(path)
+      Dir.delete(path)
     else
       File.delete(path)
     end
diff --git a/src/spec/expectation.cr b/src/spec/expectation.cr
index 3fac00c..77869cd 100644
--- a/src/spec/expectation.cr
+++ b/src/spec/expectation.cr
@@ -5,7 +5,10 @@ require "file_utils"
 module HaveFiles::Spec
   struct Expectation
     @diff : String?
-    def diff; @diff.as(String); end
+
+    def diff
+      @diff.as(String)
+    end
 
     def initialize(@expected_dir : String, @base_dir : String = "/tmp", @cleanup : Bool = true)
     end