diff --git a/js/src/jit-test/tests/gc/bug-1238582.js b/js/src/jit-test/tests/gc/bug-1238582.js
new file mode 100644
index 000000000000..60286c8eee87
--- /dev/null
+++ b/js/src/jit-test/tests/gc/bug-1238582.js
@@ -0,0 +1,4 @@
+if (!('oomTest' in this))
+    quit();
+
+oomTest(() => { let a = [2147483651]; [a[0], a[undefined]].sort(); });
diff --git a/js/src/jsarray.cpp b/js/src/jsarray.cpp
index 40e6c8475072..0512b6923d13 100644
--- a/js/src/jsarray.cpp
+++ b/js/src/jsarray.cpp
@@ -1741,7 +1741,7 @@ SortLexicographically(JSContext* cx, AutoValueVector* vec, size_t len)
     Vector<StringifiedElement, 0, TempAllocPolicy> strElements(cx);
 
     /* MergeSort uses the upper half as scratch space. */
-    if (!strElements.reserve(2 * len))
+    if (!strElements.resize(2 * len))
         return false;
 
     /* Convert Values to strings. */
@@ -1753,14 +1753,10 @@ SortLexicographically(JSContext* cx, AutoValueVector* vec, size_t len)
         if (!ValueToStringBuffer(cx, (*vec)[i], sb))
             return false;
 
-        StringifiedElement el = { cursor, sb.length(), i };
-        strElements.infallibleAppend(el);
+        strElements[i] = { cursor, sb.length(), i };
         cursor = sb.length();
     }
 
-    /* Resize strElements so we can perform MergeSort. */
-    JS_ALWAYS_TRUE(strElements.resize(2 * len));
-
     /* Sort Values in vec alphabetically. */
     return MergeSortByKey(strElements.begin(), len, strElements.begin() + len,
                           SortComparatorStringifiedElements(cx, sb), vec);
@@ -1780,7 +1776,7 @@ SortNumerically(JSContext* cx, AutoValueVector* vec, size_t len, ComparatorMatch
     Vector<NumericElement, 0, TempAllocPolicy> numElements(cx);
 
     /* MergeSort uses the upper half as scratch space. */
-    if (!numElements.reserve(2 * len))
+    if (!numElements.resize(2 * len))
         return false;
 
     /* Convert Values to numerics. */
@@ -1792,13 +1788,9 @@ SortNumerically(JSContext* cx, AutoValueVector* vec, size_t len, ComparatorMatch
         if (!ToNumber(cx, (*vec)[i], &dv))
             return false;
 
-        NumericElement el = { dv, i };
-        numElements.infallibleAppend(el);
+        numElements[i] = { dv, i };
     }
 
-    /* Resize strElements so we can perform MergeSort. */
-    JS_ALWAYS_TRUE(numElements.resize(2 * len));
-
     /* Sort Values in vec numerically. */
     return MergeSortByKey(numElements.begin(), len, numElements.begin() + len,
                           SortComparatorNumerics[comp], vec);