diff --git a/src/lsp/mp.lsp b/src/lsp/mp.lsp
index b4c4521..66dff01 100644
--- a/src/lsp/mp.lsp
+++ b/src/lsp/mp.lsp
@@ -116,16 +116,20 @@ by ALLOW-WITH-INTERRUPTS."
   ;; the get-lock statement, to ensure that the unlocking is done with
   ;; interrupts disabled.
   #+threads
-  (ext:with-unique-names (lock owner count)
+  (ext:with-unique-names (lock owner count process)
     `(let* ((,lock ,lock-form)
             (,owner (mp:lock-owner ,lock))
 	    (,count (mp:lock-count ,lock)))
+       (declare (type fixnum ,count))
        (without-interrupts
            (unwind-protect
                 (with-restored-interrupts
                     (mp::get-lock ,lock)
                   (locally ,@body))
-             (when (and (eq mp:*current-process* (mp:lock-owner ,lock))
-			(or (not (eq ,owner mp:*current-process*))
-			    (> (mp:lock-count ,lock) ,count)))
-               (mp::giveup-lock ,lock)))))))
+	     (let ((,process mp:*current-process*))
+	       (declare (optimize (speed 3) (safety 0) (debug 0)))
+	       (when (and (eq ,process (mp:lock-owner ,lock))
+			  (or (not (eq ,owner ,process))
+			      (> (the fixnum (mp:lock-count ,lock))
+				 (the fixnum ,count))))
+		 (mp::giveup-lock ,lock))))))))