diff --git a/pyproject.toml b/pyproject.toml
index ba208ef848..de41ff555f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -51,7 +51,7 @@ dependencies = [
     # c.f. https://github.com/scikit-hep/pyhf/issues/2593 for excluded v1.16.x versions
     "scipy>=1.5.2,!=1.16.0,!=1.16.1,!=1.16.2",  # requires numpy, which is required by pyhf
     "tqdm>=4.56.0",  # for readxml
-    "numpy",  # compatible versions controlled through scipy
+    "numpy!=2.3.4",  # compatible versions controlled through scipy
 ]
 
 [project.scripts]