diff --git a/Utilities/otb6S/libf2c/sysdep1.h b/Utilities/otb6S/libf2c/sysdep1.h
index 4c026a240a150b78322a76339acc38aea1b51cff..9fbd16cd9629744a0d49f9dc52a6b9d2bf702f4e 100644
--- a/Utilities/otb6S/libf2c/sysdep1.h
+++ b/Utilities/otb6S/libf2c/sysdep1.h
@@ -10,8 +10,10 @@
 
 #ifdef __linux__
 #define USE_LARGEFILE
+#ifndef OFF_T
 #define OFF_T __off64_t
 #endif
+#endif
 
 #ifdef _AIX43
 #define _LARGE_FILES
@@ -39,8 +41,12 @@
 #ifndef OFF_T
 #define OFF_T off64_t
 #endif
+#ifndef _LARGEFILE_SOURCE
 #define _LARGEFILE_SOURCE
+#endif
+#ifndef _LARGEFILE64_SOURCE
 #define _LARGEFILE64_SOURCE
+#endif
 #include <sys/types.h>
 #include <sys/stat.h>
 #define FOPEN fopen64