diff --git a/modules/libpref/init/all.js b/modules/libpref/init/all.js
index 827e0beccf54..0e5e2fe583db 100644
--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -62,8 +62,8 @@ pref("browser.cache.memory.max_entry_size",  5120);
 // (priority) like html, css, fonts and js, and one for other data like images,
 // video, etc.
 // Note: 0 means no limit.
-pref("browser.cache.disk.max_chunks_memory_usage", 10240);
-pref("browser.cache.disk.max_priority_chunks_memory_usage", 10240);
+pref("browser.cache.disk.max_chunks_memory_usage", 40960);
+pref("browser.cache.disk.max_priority_chunks_memory_usage", 40960);
 
 pref("browser.cache.disk_cache_ssl",        true);
 // 0 = once-per-session, 1 = each-time, 2 = never, 3 = when-appropriate/automatically
diff --git a/netwerk/cache2/CacheObserver.cpp b/netwerk/cache2/CacheObserver.cpp
index c9e3da01790c..bc40dd859060 100644
--- a/netwerk/cache2/CacheObserver.cpp
+++ b/netwerk/cache2/CacheObserver.cpp
@@ -62,10 +62,10 @@ int32_t CacheObserver::sMaxMemoryEntrySize = kDefaultMaxMemoryEntrySize;
 static int32_t const kDefaultMaxDiskEntrySize = 50 * 1024; // 50 MB
 int32_t CacheObserver::sMaxDiskEntrySize = kDefaultMaxDiskEntrySize;
 
-static uint32_t const kDefaultMaxDiskChunksMemoryUsage = 10 * 1024; // 10MB
+static uint32_t const kDefaultMaxDiskChunksMemoryUsage = 40 * 1024; // 40MB
 uint32_t CacheObserver::sMaxDiskChunksMemoryUsage = kDefaultMaxDiskChunksMemoryUsage;
 
-static uint32_t const kDefaultMaxDiskPriorityChunksMemoryUsage = 10 * 1024; // 10MB
+static uint32_t const kDefaultMaxDiskPriorityChunksMemoryUsage = 40 * 1024; // 40MB
 uint32_t CacheObserver::sMaxDiskPriorityChunksMemoryUsage = kDefaultMaxDiskPriorityChunksMemoryUsage;
 
 static uint32_t const kDefaultCompressionLevel = 1;