diff --git a/lib/ocran/inno_setup_builder.rb b/lib/ocran/inno_setup_builder.rb
index effc933..720d7a6 100644
--- a/lib/ocran/inno_setup_builder.rb
+++ b/lib/ocran/inno_setup_builder.rb
@@ -40,10 +40,14 @@ def initialize(path, inno_setup_script, chdir_before: nil, icon_path: nil, title
     end
 
     def compile
+      # To make ISSC output installer files relative to the working directory,
+      # it is necessary to provide the ISS file via standard input.
+      type_cmd = "type #{quote_and_escape(convert_path_to_windows(@iss.to_path))}"
       iscc_cmd = ["ISCC"]
       iscc_cmd << "/Q" unless Ocran.verbose
-      iscc_cmd << @iss.to_path
-      unless system(*iscc_cmd)
+      iscc_cmd << "-"
+      cmd = "#{type_cmd} | #{iscc_cmd.join(" ")}"
+      unless system(cmd)
         case $?.exitstatus
         when 0 then raise "ISCC reported success, but system reported error?"
         when 1 then raise "ISCC reports invalid command line parameters"
diff --git a/lib/ocran/inno_setup_script_builder.rb b/lib/ocran/inno_setup_script_builder.rb
index 63fec2a..c996bbc 100644
--- a/lib/ocran/inno_setup_script_builder.rb
+++ b/lib/ocran/inno_setup_script_builder.rb
@@ -13,10 +13,7 @@ def initialize(inno_setup_script, files: [], dirs: [])
     end
 
     def build
-      # ISSC generates the installer files relative to the directory of the
-      # ISS file. Therefore, it is necessary to create Tempfiles in the
-      # working directory.
-      @file = Tempfile.open("", Dir.pwd) do |f|
+      @file = Tempfile.open do |f|
         IO.copy_stream(@inno_setup_script, f) if @inno_setup_script
 
         unless @dirs.empty?
diff --git a/lib/ocran/windows_command_escaping.rb b/lib/ocran/windows_command_escaping.rb
index f0248ed..5057ef2 100644
--- a/lib/ocran/windows_command_escaping.rb
+++ b/lib/ocran/windows_command_escaping.rb
@@ -11,5 +11,9 @@ def escape_double_quotes(s)
     def quote_and_escape(s)
       "\"#{escape_double_quotes(s)}\""
     end
+
+    def convert_path_to_windows(s)
+      s.to_s.gsub(File::SEPARATOR, "\\")
+    end
   end
 end