diff --git a/base/src/nsString2.cpp b/base/src/nsString2.cpp
index 6feb0cb413e..580bfebb9b1 100644
--- a/base/src/nsString2.cpp
+++ b/base/src/nsString2.cpp
@@ -1676,7 +1676,7 @@ NS_BASE int fputs(const nsString2& aString, FILE* out)
   if(len>0)
     ::fwrite(cp, 1, len, out);
   if (cp != buf) {
-    delete cp;
+    delete[] cp;
   }
   return (int) len;
 }
diff --git a/string/obsolete/nsString2.cpp b/string/obsolete/nsString2.cpp
index 6feb0cb413e..580bfebb9b1 100644
--- a/string/obsolete/nsString2.cpp
+++ b/string/obsolete/nsString2.cpp
@@ -1676,7 +1676,7 @@ NS_BASE int fputs(const nsString2& aString, FILE* out)
   if(len>0)
     ::fwrite(cp, 1, len, out);
   if (cp != buf) {
-    delete cp;
+    delete[] cp;
   }
   return (int) len;
 }
diff --git a/xpcom/ds/nsString2.cpp b/xpcom/ds/nsString2.cpp
index 6feb0cb413e..580bfebb9b1 100644
--- a/xpcom/ds/nsString2.cpp
+++ b/xpcom/ds/nsString2.cpp
@@ -1676,7 +1676,7 @@ NS_BASE int fputs(const nsString2& aString, FILE* out)
   if(len>0)
     ::fwrite(cp, 1, len, out);
   if (cp != buf) {
-    delete cp;
+    delete[] cp;
   }
   return (int) len;
 }
diff --git a/xpcom/string/obsolete/nsString2.cpp b/xpcom/string/obsolete/nsString2.cpp
index 6feb0cb413e..580bfebb9b1 100644
--- a/xpcom/string/obsolete/nsString2.cpp
+++ b/xpcom/string/obsolete/nsString2.cpp
@@ -1676,7 +1676,7 @@ NS_BASE int fputs(const nsString2& aString, FILE* out)
   if(len>0)
     ::fwrite(cp, 1, len, out);
   if (cp != buf) {
-    delete cp;
+    delete[] cp;
   }
   return (int) len;
 }