diff --git a/mozilla/dom/tools/IdlScanner.cpp b/mozilla/dom/tools/IdlScanner.cpp
index 220a2a97e67..a2f0344223f 100644
--- a/mozilla/dom/tools/IdlScanner.cpp
+++ b/mozilla/dom/tools/IdlScanner.cpp
@@ -37,7 +37,7 @@ IdlScanner::IdlScanner()
   mCurrentToken = (Token*)0;
   mTokenPeeked = 0;
   mLineNumber = 1;
-  for (int i = 0; i < MAX_ID_LENGHT; i++) mTokenName[i] = 0;
+  for (int i = 0; i < MAX_ID_LENGTH; i++) mTokenName[i] = 0;
 }
 
 IdlScanner::~IdlScanner()
@@ -130,7 +130,7 @@ Token* IdlScanner::NextToken()
 
     int c = EatWhiteSpace();
     if (EOF != c) {
-      for (int i = 1; i < MAX_ID_LENGHT; i++) mTokenName[i] = 0;
+      for (int i = 1; i < MAX_ID_LENGTH; i++) mTokenName[i] = 0;
       mTokenName[0] = c;
 
       mCurrentToken->SetToken(ERROR_TOKEN);
diff --git a/mozilla/dom/tools/IdlScanner.h b/mozilla/dom/tools/IdlScanner.h
index d4ff1da2d44..e152a40e54f 100644
--- a/mozilla/dom/tools/IdlScanner.h
+++ b/mozilla/dom/tools/IdlScanner.h
@@ -31,7 +31,7 @@
 class ifstream;
 #endif
 
-#define MAX_ID_LENGHT   256
+#define MAX_ID_LENGTH   256
 
 enum EIDLTokenType {
   EOF_TOKEN = -1,
@@ -170,7 +170,7 @@ private:
   Token *mCurrentToken;
   long mLineNumber;
   int mTokenPeeked;
-  char mTokenName[MAX_ID_LENGHT];
+  char mTokenName[MAX_ID_LENGTH];
 
 public:
             IdlScanner();