diff --git a/CHANGELOG.md b/CHANGELOG.md
index ea926a6..ddd0bd1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## HEAD (unreleased)
 
+- Fix windows filename detection (https://github.com/zombocom/dead_end/pull/114)
 - Update links on readme and code of conduct (https://github.com/zombocom/dead_end/pull/107)
 
 ## 3.0.1
diff --git a/lib/dead_end.rb b/lib/dead_end.rb
index 566e7d0..fcbcb8b 100644
--- a/lib/dead_end.rb
+++ b/lib/dead_end.rb
@@ -17,12 +17,14 @@ class Error < StandardError; end
   TIMEOUT_DEFAULT = ENV.fetch("DEAD_END_TIMEOUT", 1).to_i
 
   def self.handle_error(e)
-    filename = e.message.split(":").first
+    file = PathnameFromMessage.new(e.message).call.name
+    raise e unless file
+
     $stderr.sync = true
 
     call(
-      source: Pathname(filename).read,
-      filename: filename
+      source: file.read,
+      filename: file
     )
 
     raise e
@@ -139,21 +141,24 @@ def self.valid?(source)
   end
 end
 
-require_relative "dead_end/code_line"
-require_relative "dead_end/code_block"
+# Integration
+require_relative "dead_end/cli"
+require_relative "dead_end/auto"
+
+# Core logic
 require_relative "dead_end/code_search"
 require_relative "dead_end/code_frontier"
+require_relative "dead_end/explain_syntax"
 require_relative "dead_end/clean_document"
 
+# Helpers
 require_relative "dead_end/lex_all"
+require_relative "dead_end/code_line"
+require_relative "dead_end/code_block"
 require_relative "dead_end/block_expand"
+require_relative "dead_end/ripper_errors"
 require_relative "dead_end/insertion_sort"
 require_relative "dead_end/around_block_scan"
-require_relative "dead_end/ripper_errors"
+require_relative "dead_end/pathname_from_message"
 require_relative "dead_end/display_invalid_blocks"
 require_relative "dead_end/parse_blocks_from_indent_line"
-
-require_relative "dead_end/explain_syntax"
-
-require_relative "dead_end/auto"
-require_relative "dead_end/cli"
diff --git a/lib/dead_end/pathname_from_message.rb b/lib/dead_end/pathname_from_message.rb
new file mode 100644
index 0000000..e3141eb
--- /dev/null
+++ b/lib/dead_end/pathname_from_message.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module DeadEnd
+  # Converts a SyntaxError message to a path
+  #
+  # Handles the case where the filename has a colon in it
+  # such as on a windows file system: https://github.com/zombocom/dead_end/issues/111
+  #
+  # Example:
+  #
+  #    message = "/tmp/scratch:2:in `require_relative': /private/tmp/bad.rb:1: syntax error, unexpected `end' (SyntaxError)"
+  #    puts PathnameFromMessage.new(message).call.name
+  #    # => "/tmp/scratch.rb"
+  #
+  class PathnameFromMessage
+    attr_reader :name
+
+    def initialize(message, io: $stderr)
+      @line = message.lines.first
+      @parts = @line.split(":")
+      @guess = []
+      @name = nil
+      @io = io
+    end
+
+    def call
+      until stop?
+        @guess << @parts.shift
+        @name = Pathname(@guess.join(":"))
+      end
+
+      if @parts.empty?
+        @io.puts "DeadEnd: could not find filename from #{@line.inspect}"
+        @name = nil
+      end
+
+      self
+    end
+
+    def stop?
+      return true if @parts.empty?
+      return false if @guess.empty?
+
+      @name&.exist?
+    end
+  end
+end
diff --git a/spec/unit/pathname_from_message_spec.rb b/spec/unit/pathname_from_message_spec.rb
new file mode 100644
index 0000000..e570aac
--- /dev/null
+++ b/spec/unit/pathname_from_message_spec.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require_relative "../spec_helper"
+
+module DeadEnd
+  RSpec.describe "PathnameFromMessage" do
+    it "handles filenames with colons in them" do
+      Dir.mktmpdir do |dir|
+        dir = Pathname(dir)
+
+        file = dir.join("scr:atch.rb").tap { |p| FileUtils.touch(p) }
+
+        message = "#{file}:2:in `require_relative': /private/tmp/bad.rb:1: syntax error, unexpected `end' (SyntaxError)"
+        file = PathnameFromMessage.new(message).call.name
+
+        expect(file).to be_truthy
+      end
+    end
+
+    it "checks if the file exists" do
+      Dir.mktmpdir do |dir|
+        dir = Pathname(dir)
+
+        file = dir.join("scratch.rb")
+
+        message = "#{file}:2:in `require_relative': /private/tmp/bad.rb:1: syntax error, unexpected `end' (SyntaxError)"
+        io = StringIO.new
+        file = PathnameFromMessage.new(message, io: io).call.name
+
+        expect(io.string).to include(file.to_s)
+        expect(file).to be_falsey
+      end
+    end
+  end
+end