diff --git a/libc/kernel/tools/clean_header.py b/libc/kernel/tools/clean_header.py
index 01569fc..1a5471a 100755
--- a/libc/kernel/tools/clean_header.py
+++ b/libc/kernel/tools/clean_header.py
@@ -66,6 +66,9 @@
     if arch and arch in kernel_default_arch_macros:
         macros.update(kernel_default_arch_macros[arch])
 
+    if arch and arch in kernel_arch_token_replacements:
+        blocks.replaceTokens( kernel_arch_token_replacements[arch] )
+
     blocks.optimizeMacros( macros )
     blocks.optimizeIf01()
     blocks.removeVarsAndFuncs( statics )
diff --git a/libc/kernel/tools/defaults.py b/libc/kernel/tools/defaults.py
index 6c7efd6..da02481 100644
--- a/libc/kernel/tools/defaults.py
+++ b/libc/kernel/tools/defaults.py
@@ -48,6 +48,11 @@
     "mips": {"CONFIG_32BIT":"1"},
     }
 
+kernel_arch_token_replacements = {
+    "arm": {},
+    "x86": {},
+    "mips": {"off_t":"__kernel_off_t"},
+    }
 # Replace tokens in the output according to this mapping
 kernel_token_replacements = {
     "asm": "__asm__",