diff --git a/dtool/Config.Linux.pp b/dtool/Config.Linux.pp
index 3f4e0e0c05..18d8dd7873 100644
--- a/dtool/Config.Linux.pp
+++ b/dtool/Config.Linux.pp
@@ -127,3 +127,7 @@
 // What is the syntax of the STL allocator declaration?  See
 // LocalSetup.pp for allowable values.
 #define STL_ALLOCATOR GNU
+
+// large file >2GB support
+#define _LARGEFILE_SOURCE 1
+#define _FILE_OFFSET_BITS 64