diff --git a/src/write.jl b/src/write.jl
index 92fd27a..e51344e 100644
--- a/src/write.jl
+++ b/src/write.jl
@@ -68,8 +68,8 @@ function update_table_style!(unzipped_ppt_dir::String=".")
     end
 end
 
-function add_contenttypes!()
-    path = joinpath("..", "[Content_Types].xml")
+function add_contenttypes!(unzipped_ppt_dir::String=".")
+    path = abspath(joinpath(unzipped_ppt_dir, "..", "[Content_Types].xml"))
     doc = readxml(path)
     r = root(doc)
     extension_contenttypes = (
diff --git a/test/testWriting.jl b/test/testWriting.jl
index 63e9da6..2b7fdfe 100644
--- a/test/testWriting.jl
+++ b/test/testWriting.jl
@@ -112,6 +112,10 @@ end
         media_dir = joinpath(edited_template_path, "ppt", "media")
         mkdir(media_dir)
 
+        # extra complexity: support read-only template support
+        # see https://github.com/ASML-Labs/PPTX.jl/issues/45
+        chmod(edited_template_path, 0o444; recursive=true)
+
         pres = Presentation(;title="My Presentation")
         s1 = Slide()
         julia_logo = Picture(joinpath(PPTX.ASSETS_DIR,"julia_logo.png"), top = 110, left = 110)
@@ -124,4 +128,4 @@ end
 
         @test isfile(pptx_path)
     end
-end
\ No newline at end of file
+end