diff --git a/sphinxcontrib/katex.py b/sphinxcontrib/katex.py
index f4a50f3..8a784b9 100644
--- a/sphinxcontrib/katex.py
+++ b/sphinxcontrib/katex.py
@@ -392,8 +392,8 @@ def build_command(cls, socket=None, port=None):
             # without `.js` at the end
             print(f"DEBUG: giveb {cls.KATEX_PATH=}")
             katex_path = os.path.relpath(str(cls.KATEX_PATH))[:-3]
-            # relative path had to start with `"./"` for `require()` 
-            katex_path = os.path.join("./", katex_path)
+            # relative path had to start with `"./"` for `require()`
+            katex_path = os.path.join("./../sphinxcontrib/", katex_path)
             print(f"DEBUG: add {katex_path=}")
             cmd.extend(["--katex", katex_path])
         else: