diff --git a/pyproject.toml b/pyproject.toml
index f3b48273f..836d857f8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -41,7 +41,7 @@ dependencies = [
     "highspy >= 1.5.3",  # Default solver
     "pandas >= 2, < 3",  # Used in post-processing
     "matplotlib >= 3.5.2",  # Used in post-processing
-    "plotly >= 5.15",  # Used in post-processing
+    "plotly >= 5.15, < 6",  # Used in post-processing
     "tomli >= 2.0.1"  # TOML parser (only needed until python 3.11)
 ]