diff --git a/js/public/HeapAPI.h b/js/public/HeapAPI.h
index 5607afce1d3..37784136957 100644
--- a/js/public/HeapAPI.h
+++ b/js/public/HeapAPI.h
@@ -98,7 +98,7 @@ namespace JS {
 struct Zone;
 
 /* Default size for the generational nursery in bytes. */
-const uint32_t DefaultNurseryBytes = 16 * ChunkSize;
+const uint32_t DefaultNurseryBytes = 16 * 1024 * 1024;
 
 /* Default maximum heap size in bytes to pass to JS_NewRuntime(). */
 const uint32_t DefaultHeapMaxBytes = 32 * 1024 * 1024;
diff --git a/js/src/gc/Nursery.h b/js/src/gc/Nursery.h
index a031e348511..7efa372380e 100644
--- a/js/src/gc/Nursery.h
+++ b/js/src/gc/Nursery.h
@@ -71,7 +71,7 @@ class Nursery
     {}
     ~Nursery();
 
-    bool init(uint32_t maxNurseryBytes);
+    bool init(uint32_t numNurseryChunks);
 
     bool exists() const { return numNurseryChunks_ != 0; }
     size_t numChunks() const { return numNurseryChunks_; }