diff --git a/gfx/ots/README.mozilla b/gfx/ots/README.mozilla
index 221ddc4db90..c32e8db82db 100644
--- a/gfx/ots/README.mozilla
+++ b/gfx/ots/README.mozilla
@@ -1,6 +1,6 @@
 This is the Sanitiser for OpenType project, from http://code.google.com/p/ots/.
 
-Current revision: r91
+Current revision: r92
 
 Applied local patches:
     ots-fix-vc10.patch - workaround for VS10 STL wrappers (bug 602558)
diff --git a/gfx/ots/src/ots.cc b/gfx/ots/src/ots.cc
index 07a980f076f..25b9ed26733 100644
--- a/gfx/ots/src/ots.cc
+++ b/gfx/ots/src/ots.cc
@@ -185,7 +185,9 @@ bool IsValidVersionTag(uint32_t tag) {
          tag == Tag("typ1");
 }
 
-bool ProcessGeneric(ots::OpenTypeFile *header, ots::OTSStream *output,
+bool ProcessGeneric(ots::OpenTypeFile *header,
+                    uint32_t signature,
+                    ots::OTSStream *output,
                     const uint8_t *data, size_t length,
                     const std::vector<OpenTypeTable>& tables,
                     ots::Buffer& file);
@@ -263,7 +265,8 @@ bool ProcessTTF(ots::OpenTypeFile *header,
     tables.push_back(table);
   }
 
-  return ProcessGeneric(header, output, data, length, tables, file);
+  return ProcessGeneric(header, header->version, output, data, length,
+                        tables, file);
 }
 
 bool ProcessWOFF(ots::OpenTypeFile *header,
@@ -421,10 +424,11 @@ bool ProcessWOFF(ots::OpenTypeFile *header,
     return OTS_FAILURE_MSG_HDR("file length mismatch (trailing junk?)");
   }
 
-  return ProcessGeneric(header, output, data, length, tables, file);
+  return ProcessGeneric(header, woff_tag, output, data, length, tables, file);
 }
 
-bool ProcessGeneric(ots::OpenTypeFile *header, ots::OTSStream *output,
+bool ProcessGeneric(ots::OpenTypeFile *header, uint32_t signature,
+                    ots::OTSStream *output,
                     const uint8_t *data, size_t length,
                     const std::vector<OpenTypeTable>& tables,
                     ots::Buffer& file) {
@@ -485,10 +489,11 @@ bool ProcessGeneric(ots::OpenTypeFile *header, ots::OTSStream *output,
     }
     // since we required that the file be < 1GB in length, and that the table
     // length is < 1GB, the following addtion doesn't overflow
-    const uint32_t end_byte = tables[i].offset + tables[i].length;
-    // Some fonts which are automatically generated by a font generator
-    // called TTX seems not to add 0-padding to the final table. It might be
-    // ok to accept these fonts so we round up the length of the font file.
+    uint32_t end_byte = tables[i].offset + tables[i].length;
+    // Tables in the WOFF file must be aligned 4-byte boundary.
+    if (signature == Tag("wOFF")) {
+        end_byte = Round4(end_byte);
+    }
     if (!end_byte || end_byte > length) {
       return OTS_FAILURE_MSG_TAG("table overruns end of file", &tables[i].tag);
     }