1 files changed, 3 insertions, 3 deletions

diff --git a/shell/math.c b/shell/math.c
index 2959e57ea..56f866bf2 100644
--- a/shell/math.c
+++ b/shell/math.c
@@ -889,9 +889,9 @@ dbg("    numstack:%d val:%lld '%s'", (int)(numstackptr - numstack), numstackptr[
                                  */
                                 if (math_state->evaluation_disabled & TOP_BIT_ULL)
                                         goto err; /* >63 levels of ?: nesting not supported */
-                                math_state->evaluation_disabled <<= 1;
-                                if (numstackptr[-1].val == 0)
-                                        math_state->evaluation_disabled |= 1;
+                                math_state->evaluation_disabled =
+                                        (math_state->evaluation_disabled << 1)
+                                        | (numstackptr[-1].val == 0);
                                 dbg("'?' entered: evaluation_disabled=%llx", EVAL_DISABLED);
                         }
                 } /* if */