diff --git a/srcpkgs/icecat/patches/sandbox-largefile.patch b/srcpkgs/icecat/patches/sandbox-largefile.patch
new file mode 100644
index 00000000000..494ca82df5a
--- /dev/null
+++ b/srcpkgs/icecat/patches/sandbox-largefile.patch
@@ -0,0 +1,17 @@
+--- security/sandbox/linux/SandboxFilter.cpp	2020-11-23 22:41:14.556378950 +0100
++++ security/sandbox/linux/SandboxFilter.cpp	2020-11-23 22:40:23.595806444 +0100
+@@ -68,7 +68,13 @@
+ 
+ // The headers define O_LARGEFILE as 0 on x86_64, but we need the
+ // actual value because it shows up in file flags.
+-#define O_LARGEFILE_REAL 00100000
++#if defined(__x86_64__) || defined(__i386__) || defined(__mips__)
++#define O_LARGEFILE_REAL 0100000
++#elif defined(__powerpc__)
++#define O_LARGEFILE_REAL 0200000
++#else
++#define O_LARGEFILE_REAL O_LARGEFILE
++#endif
+ 
+ // Not part of UAPI, but userspace sees it in F_GETFL; see bug 1650751.
+ #define FMODE_NONOTIFY 0x4000000