diff --git a/gcc/config/aarch64/aarch64-c.cc b/gcc/config/aarch64/aarch64-c.cc
index e296c73350f1ec70f6017c11be54e0749bf114d5..e47b6a870e20867003393d7496f761e47057e804 100644
--- a/gcc/config/aarch64/aarch64-c.cc
+++ b/gcc/config/aarch64/aarch64-c.cc
@@ -195,6 +195,8 @@ aarch64_update_cpp_builtins (cpp_reader *pfile)
       builtin_define_with_int_value ("__ARM_FEATURE_PAC_DEFAULT", v);
     }
 
+  aarch64_def_or_undef (TARGET_PAUTH, "__ARM_FEATURE_PAUTH", pfile);
+  aarch64_def_or_undef (TARGET_BTI, "__ARM_FEATURE_BTI", pfile);
   aarch64_def_or_undef (TARGET_I8MM, "__ARM_FEATURE_MATMUL_INT8", pfile);
   aarch64_def_or_undef (TARGET_BF16_SIMD,
 			"__ARM_FEATURE_BF16_VECTOR_ARITHMETIC", pfile);
diff --git a/gcc/config/aarch64/aarch64.h b/gcc/config/aarch64/aarch64.h
index dcb1ecef71a937ece4d9849161157541855ab638..db6ec5c48d8f57d57c983f410315cdffe8d45a27 100644
--- a/gcc/config/aarch64/aarch64.h
+++ b/gcc/config/aarch64/aarch64.h
@@ -312,6 +312,11 @@ enum class aarch64_feature : unsigned char {
 /* PAUTH instructions are enabled through +pauth.  */
 #define TARGET_PAUTH (AARCH64_ISA_PAUTH)
 
+/* BTI instructions exist from Armv8.5-a onwards.  Their automatic use is
+   enabled through -mbranch-protection by using NOP-space instructions,
+   but this TARGET_ is used for defining BTI-related ACLE things.  */
+#define TARGET_BTI (AARCH64_ISA_V8_5A)
+
 /* MOPS instructions are enabled through +mops.  */
 #define TARGET_MOPS (AARCH64_ISA_MOPS)
 
diff --git a/gcc/testsuite/gcc.target/aarch64/acle/bti_def.c b/gcc/testsuite/gcc.target/aarch64/acle/bti_def.c
new file mode 100644
index 0000000000000000000000000000000000000000..db94769ec8b9dcad2b0f3b84753ad4b8d7d4b412
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/acle/bti_def.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+#pragma GCC target "arch=armv8.5-a"
+#ifndef __ARM_FEATURE_BTI
+#error "__ARM_FEATURE_BTI is not defined but should be!"
+#endif
+
+void
+foo (void) {}
+
diff --git a/gcc/testsuite/gcc.target/aarch64/acle/pauth_def.c b/gcc/testsuite/gcc.target/aarch64/acle/pauth_def.c
new file mode 100644
index 0000000000000000000000000000000000000000..400a0f61deb0749b3512322fad637a4c793b0dfb
--- /dev/null
+++ b/gcc/testsuite/gcc.target/aarch64/acle/pauth_def.c
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+
+#pragma GCC target "+pauth"
+#ifndef __ARM_FEATURE_PAUTH
+#error "__ARM_FEATURE_PAUTH is not defined but should be!"
+#endif
+
+void
+foo (void) {}
+