diff --git a/libc/kernel/tools/cpp.py b/libc/kernel/tools/cpp.py
index 04e4256..2c40d7c 100644
--- a/libc/kernel/tools/cpp.py
+++ b/libc/kernel/tools/cpp.py
@@ -1521,7 +1521,7 @@
         """replace tokens according to the given dict
            """
         for b in self.blocks:
-            if not b.isDirective():
+            if (not b.isDirective()) or b.isDefine():
                 for tok in b.tokens:
                     if tok.id == tokIDENT:
                         if tok.value in replacements: