diff --git a/mozilla/layout/generic/nsObjectFrame.cpp b/mozilla/layout/generic/nsObjectFrame.cpp
index 5262233273a..8da7151dab6 100644
--- a/mozilla/layout/generic/nsObjectFrame.cpp
+++ b/mozilla/layout/generic/nsObjectFrame.cpp
@@ -2632,10 +2632,17 @@ NS_IMETHODIMP nsPluginInstanceOwner::GetDocumentBase(const char* *result)
 
 static nsHashtable *gCharsetMap = nsnull;
 typedef struct {
-    char *mozName;
-    char *javaName;
+    char mozName[16];
+    char javaName[12];
 } moz2javaCharset;
 
+/* XXX If you add any strings longer than
+ *  {"x-mac-cyrillic",  "MacCyrillic"},
+ *  {"x-mac-ukrainian", "MacUkraine"},
+ * to the following array then you MUST update the
+ * sizes of the arrays in the moz2javaCharset struct
+ */
+
 static const moz2javaCharset charsets[] = 
 {
     {"windows-1252",    "Cp1252"},
diff --git a/mozilla/layout/html/base/src/nsObjectFrame.cpp b/mozilla/layout/html/base/src/nsObjectFrame.cpp
index 5262233273a..8da7151dab6 100644
--- a/mozilla/layout/html/base/src/nsObjectFrame.cpp
+++ b/mozilla/layout/html/base/src/nsObjectFrame.cpp
@@ -2632,10 +2632,17 @@ NS_IMETHODIMP nsPluginInstanceOwner::GetDocumentBase(const char* *result)
 
 static nsHashtable *gCharsetMap = nsnull;
 typedef struct {
-    char *mozName;
-    char *javaName;
+    char mozName[16];
+    char javaName[12];
 } moz2javaCharset;
 
+/* XXX If you add any strings longer than
+ *  {"x-mac-cyrillic",  "MacCyrillic"},
+ *  {"x-mac-ukrainian", "MacUkraine"},
+ * to the following array then you MUST update the
+ * sizes of the arrays in the moz2javaCharset struct
+ */
+
 static const moz2javaCharset charsets[] = 
 {
     {"windows-1252",    "Cp1252"},