@@ -106,6 +106,11 @@ pub(crate) mod _thread {
 
     fn validate_acquire_args(args: AcquireArgs, vm: &VirtualMachine) -> PyResult<(bool, f64)> {
         let timeout = args.timeout.to_secs_f64();
+        // CPython checks the signed nanosecond range before acquire-specific restrictions.
+        let timeout_ns = timeout * 1_000_000_000.0;
+        if !(i64::MIN as f64..-(i64::MIN as f64)).contains(&timeout_ns) {
+            return Err(vm.new_overflow_error("timestamp out of range for C PyTime_t"));
+        }
         if !args.blocking && timeout != -1.0 {
             return Err(vm.new_value_error("can't specify a timeout for a non-blocking call"));
         }
 
@@ -9,6 +9,16 @@
     (ValueError, {"blocking": False, "timeout": 1}),
     (ValueError, {"timeout": -2}),
     (OverflowError, {"timeout": _thread.TIMEOUT_MAX + 1}),
+    (OverflowError, {"blocking": False, "timeout": 2**63 / 1e9}),
+    (OverflowError, {"blocking": False, "timeout": -9_223_372_037}),
+    (OverflowError, {"timeout": -9_223_372_037}),
+    (OverflowError, {"blocking": False, "timeout": float("inf")}),
+    (OverflowError, {"timeout": float("inf")}),
+    (OverflowError, {"blocking": False, "timeout": float("-inf")}),
+    (OverflowError, {"timeout": float("-inf")}),
+    (ValueError, {"timeout": -(2**63) / 1e9}),
+    (ValueError, {"blocking": False, "timeout": 4_294_968}),
+    (ValueError, {"timeout": -4_294_968}),
 ):
     lock = _thread.RLock()
     assert lock.acquire()