diff --git a/mozilla/netwerk/cache/src/nsDiskCacheDevice.cpp b/mozilla/netwerk/cache/src/nsDiskCacheDevice.cpp
index 6e7fdd1b6f0..2dff6f16956 100644
--- a/mozilla/netwerk/cache/src/nsDiskCacheDevice.cpp
+++ b/mozilla/netwerk/cache/src/nsDiskCacheDevice.cpp
@@ -631,8 +631,15 @@ nsDiskCacheDevice::OnDataSizeChange(nsCacheEntry * entry, PRInt32 deltaSize)
 
     NS_ASSERTION(binding->mRecord.ValidRecord(), "bad record");
 
+    PRUint32  newSize = entry->DataSize() + deltaSize;
+    if (newSize > mCacheCapacity) {
+        nsresult rv = nsCacheService::GlobalInstance()->DoomEntry_Locked(entry);
+        NS_ASSERTION(NS_SUCCEEDED(rv),"DoomEntry_Locked() failed.");
+        return NS_ERROR_ABORT;
+    }
+
     PRUint32  sizeK = ((entry->DataSize() + 0x0399) >> 10); // round up to next 1k
-    PRUint32  newSizeK =  ((entry->DataSize() + deltaSize + 0x399) >> 10);
+    PRUint32  newSizeK =  ((newSize + 0x399) >> 10);
 
     NS_ASSERTION((sizeK < USHRT_MAX) && (sizeK == binding->mRecord.DataFileSize()),
                  "data size out of sync");
diff --git a/mozilla/netwerk/cache/src/nsMemoryCacheDevice.cpp b/mozilla/netwerk/cache/src/nsMemoryCacheDevice.cpp
index 4eb9d39889a..0e0c8cf7a16 100644
--- a/mozilla/netwerk/cache/src/nsMemoryCacheDevice.cpp
+++ b/mozilla/netwerk/cache/src/nsMemoryCacheDevice.cpp
@@ -250,6 +250,12 @@ nsMemoryCacheDevice::OnDataSizeChange( nsCacheEntry * entry, PRInt32 deltaSize)
 {
     if (entry->IsStreamData()) {
         // we have the right to refuse or pre-evict
+        PRUint32  newSize = entry->DataSize() + deltaSize;
+        if (newSize > mSoftLimit) {
+            nsresult rv = nsCacheService::GlobalInstance()->DoomEntry_Locked(entry);
+            NS_ASSERTION(NS_SUCCEEDED(rv),"DoomEntry_Locked() failed.");
+            return NS_ERROR_ABORT;
+        }
     }
 
     // adjust our totals