diff --git a/libc/bionic/heap_tagging.cpp b/libc/bionic/heap_tagging.cpp
index 62b5f5c..e5e8ec3 100644
--- a/libc/bionic/heap_tagging.cpp
+++ b/libc/bionic/heap_tagging.cpp
@@ -46,7 +46,8 @@
   // or hardware doesn't support MTE, and we will fall back to just enabling tagged pointers in
   // syscall arguments.
   if (prctl(PR_SET_TAGGED_ADDR_CTRL,
-            PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_ASYNC | (1 << PR_MTE_EXCL_SHIFT), 0, 0, 0) == 0) {
+            PR_TAGGED_ADDR_ENABLE | PR_MTE_TCF_ASYNC | (0xfffe << PR_MTE_TAG_SHIFT), 0, 0,
+            0) == 0) {
     heap_tagging_level = M_HEAP_TAGGING_LEVEL_ASYNC;
     return;
   }
diff --git a/libc/platform/bionic/mte_kernel.h b/libc/platform/bionic/mte_kernel.h
index 2c777c9..984d17d 100644
--- a/libc/platform/bionic/mte_kernel.h
+++ b/libc/platform/bionic/mte_kernel.h
@@ -37,7 +37,7 @@
 
 #ifdef ANDROID_EXPERIMENTAL_MTE
 
-#define HWCAP2_MTE (1 << 10)
+#define HWCAP2_MTE (1 << 18)
 #define PROT_MTE 0x20
 
 #define PR_MTE_TCF_SHIFT 1
@@ -45,10 +45,10 @@
 #define PR_MTE_TCF_SYNC (1UL << PR_MTE_TCF_SHIFT)
 #define PR_MTE_TCF_ASYNC (2UL << PR_MTE_TCF_SHIFT)
 #define PR_MTE_TCF_MASK (3UL << PR_MTE_TCF_SHIFT)
-#define PR_MTE_EXCL_SHIFT 3
-#define PR_MTE_EXCL_MASK (0xffffUL << PR_MTE_EXCL_SHIFT)
+#define PR_MTE_TAG_SHIFT 3
+#define PR_MTE_TAG_MASK (0xffffUL << PR_MTE_TAG_SHIFT)
 
-#define SEGV_MTEAERR 6
-#define SEGV_MTESERR 7
+#define SEGV_MTEAERR 8
+#define SEGV_MTESERR 9
 
 #endif