diff --git a/headers/os/net/HttpForm.h b/headers/os/net/HttpForm.h
index b4eba439de..6936e1ede5 100644
--- a/headers/os/net/HttpForm.h
+++ b/headers/os/net/HttpForm.h
@@ -32,7 +32,11 @@ private:
 	// but never used (see BHttpForm::operator[] which does the necessary
 	// check up)
 								BHttpFormData();
+#if __GNUC__ >= 6
+	friend class std::pair<const BString, BHttpFormData>;
+#else
 	friend class std::map<BString, BHttpFormData>;
+#endif
 
 public:
 								BHttpFormData(const BString& name,