diff --git a/.github/requirements-old.txt b/.github/requirements-old.txt
index 753ec32..88f47f1 100644
--- a/.github/requirements-old.txt
+++ b/.github/requirements-old.txt
@@ -1,6 +1,6 @@
 # Ensure changes to these dependencies are reflected in pyproject.toml
 attrs==23.1.0
 matplotlib==3.9.0
-numpy==2.0.0
+numpy==1.26.4
 scipy==1.13.0
 typing-extensions==4.8.0
diff --git a/pyproject.toml b/pyproject.toml
index 23787d2..8790f3b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -32,7 +32,7 @@ dependencies = [
     # Ensure changes to these dependencies are reflected in .github/requirements-old.txt
     "attrs>=23.1.0",
     "matplotlib>=3.9.0",
-    "numpy>=2.0.0",
+    "numpy>=1.26.4",
     "scipy>=1.13.0",
     "typing-extensions>=4.8.0; python_version < '3.11'",
 ]