diff --git a/libc/elf/def.h b/libc/elf/def.h
index a322684a7..8530592c0 100644
--- a/libc/elf/def.h
+++ b/libc/elf/def.h
@@ -86,7 +86,8 @@
 #define EM_BPF       247
 
 /* the ape flag, "lol cat 5" */
-#define EF_APE_MODERN 0x101ca75
+#define EF_APE_MODERN      0x101ca75
+#define EF_APE_MODERN_MASK 0x1ffffff
 
 #define GRP_COMDAT 1
 #define STN_UNDEF  0
diff --git a/tool/build/fixupobj.c b/tool/build/fixupobj.c
index 61f10530a..9b26ff8b6 100644
--- a/tool/build/fixupobj.c
+++ b/tool/build/fixupobj.c
@@ -332,7 +332,8 @@ static void UseFreebsdOsAbi(void) {
 }
 
 static void WriteApeFlags(void) {
-  elf->e_flags |= EF_APE_MODERN;
+  /* try to be forward-compatible */
+  elf->e_flags = (elf->e_flags & ~EF_APE_MODERN_MASK) | EF_APE_MODERN;
 }
 
 /**