diff --git a/Objects/setobject.c b/Objects/setobject.c
--- a/Objects/setobject.c
+++ b/Objects/setobject.c
@@ -138,17 +138,27 @@
     setentry *entry;
     size_t perturb = hash;
     size_t mask = (size_t)so->mask;
-    size_t i = (size_t)hash;
+    size_t i = (size_t)hash & mask;
     size_t j;
 
     while (1) {
-        for (j = 0 ; j <= LINEAR_PROBES ; j++) {
-            entry = &table[(i + j) & mask];
-            if (entry->key == NULL)
-                goto found_null;
+        if (i + LINEAR_PROBES <= mask) {
+            for (j = 0 ; j <= LINEAR_PROBES ; j++) {
+                entry = &table[i + j];
+                if (entry->key == NULL)
+                    goto found_null;
+            }
+
+        } else {
+            for (j = 0 ; j <= LINEAR_PROBES ; j++) {
+                entry = &table[(i + j) & mask];
+                if (entry->key == NULL)
+                    goto found_null;
+            }
         }
         perturb >>= PERTURB_SHIFT;
         i = i * 5 + 1 + perturb;
+        i &= mask;
     }
   found_null:
     entry->key = key;