diff --git a/pyproject.toml b/pyproject.toml
index d575fede..1feed8a3 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,11 +17,11 @@ requires = [
 
     # default numpy requirements
     "numpy==1.22.4; python_version<='3.10' and platform_python_implementation != 'PyPy'",
-    "numpy==1.23.2; python_version=='3.11' and platform_python_implementation != 'PyPy'",
+    "numpy==1.23.3; python_version=='3.11' and platform_python_implementation != 'PyPy'",
     # For Python versions which aren't yet officially supported, we specify an
     # unpinned NumPy which allows source distributions to be used and allows
     # wheels to be used as soon as they become available.
-    "numpy>=1.26.0b1; python_version>='3.12'",
+    "numpy>=1.26.0b1; python_version>='3.12rc2'",
     "numpy; python_version>='3.9' and platform_python_implementation=='PyPy'",
 ]