diff --git a/src/music.c b/src/music.c
index ff667e03c..045e6e839 100644
--- a/src/music.c
+++ b/src/music.c
@@ -415,9 +415,9 @@ do_earthquake(int force)
                         selftouch("Falling, you");
                     } else if (u.utrap && u.utraptype == TT_PIT) {
                         boolean keepfooting =
-                                ((Fumbling && !rn2(5))
-                                 || (!rnl(Role_if(PM_ARCHEOLOGIST) ? 3 : 9))
-                                 || ((ACURR(A_DEX) > 7) && rn2(5)));
+                                (!(Fumbling && rn2(5))
+                                 && (!(rnl(Role_if(PM_ARCHEOLOGIST) ? 3 : 9))
+                                     || ((ACURR(A_DEX) > 7) && rn2(5))));
 
                         You("are jostled around violently!");
                         set_utrap(rn1(6, 2), TT_PIT);