diff --git a/string/obsolete/nsString.h b/string/obsolete/nsString.h
index ec097d5e5411..7752c0722043 100644
--- a/string/obsolete/nsString.h
+++ b/string/obsolete/nsString.h
@@ -793,7 +793,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
 #endif
 
diff --git a/string/obsolete/nsString2.h b/string/obsolete/nsString2.h
index 5152ceebe4cd..15b7e27379da 100644
--- a/string/obsolete/nsString2.h
+++ b/string/obsolete/nsString2.h
@@ -887,7 +887,7 @@ private:
   void InsertWithConversion( const PRUnichar*, PRUint32, PRInt32=-1 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
 #endif
 
diff --git a/xpcom/ds/nsString.h b/xpcom/ds/nsString.h
index ec097d5e5411..7752c0722043 100644
--- a/xpcom/ds/nsString.h
+++ b/xpcom/ds/nsString.h
@@ -793,7 +793,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
 #endif
 
diff --git a/xpcom/ds/nsString2.h b/xpcom/ds/nsString2.h
index 5152ceebe4cd..15b7e27379da 100644
--- a/xpcom/ds/nsString2.h
+++ b/xpcom/ds/nsString2.h
@@ -887,7 +887,7 @@ private:
   void InsertWithConversion( const PRUnichar*, PRUint32, PRInt32=-1 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
 #endif
 
diff --git a/xpcom/string/obsolete/nsString.h b/xpcom/string/obsolete/nsString.h
index ec097d5e5411..7752c0722043 100644
--- a/xpcom/string/obsolete/nsString.h
+++ b/xpcom/string/obsolete/nsString.h
@@ -793,7 +793,7 @@ private:
   void InsertWithConversion( char, PRUint32 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsCString, char)
 #endif
 
diff --git a/xpcom/string/obsolete/nsString2.h b/xpcom/string/obsolete/nsString2.h
index 5152ceebe4cd..15b7e27379da 100644
--- a/xpcom/string/obsolete/nsString2.h
+++ b/xpcom/string/obsolete/nsString2.h
@@ -887,7 +887,7 @@ private:
   void InsertWithConversion( const PRUnichar*, PRUint32, PRInt32=-1 );
 };
 
-#if 0//def NEW_STRING_APIS
+#ifdef NEW_STRING_APIS
 NS_DEF_STRING_COMPARISON_OPERATORS(nsString, PRUnichar)
 #endif