diff --git a/python-cramjam.spec b/python-cramjam.spec
index 2434432..b734390 100644
--- a/python-cramjam.spec
+++ b/python-cramjam.spec
@@ -118,6 +118,10 @@ do
   fi
 done
 
+# EPEL10.0: SemVer-incompatible PyO3 0.24 blocked by policy, so use 0.23.
+tomcli set Cargo.toml str dependencies.pyo3.version '^0.23'
+tomcli set Cargo.toml str build-dependencies.pyo3-build-config '^0.23'
+
 %cargo_prep