diff --git a/app/boards/native_sim_libfuzzer.conf b/app/boards/native_sim_libfuzzer.conf
index ba17224424cf..096bfe9dea47 100644
--- a/app/boards/native_sim_libfuzzer.conf
+++ b/app/boards/native_sim_libfuzzer.conf
@@ -5,7 +5,7 @@ CONFIG_ASSERT=y
 CONFIG_EXCEPTION_DEBUG=y
 CONFIG_ARCH_POSIX_TRAP_ON_FATAL=y
 CONFIG_SYS_HEAP_BIG_ONLY=y
-CONFIG_SYS_HEAP_HARDENING_EXTREME=y
+CONFIG_SYS_HEAP_HARDENING_FULL=y
 CONFIG_STACK_SENTINEL=y
 CONFIG_ZEPHYR_NATIVE_DRIVERS=y
 CONFIG_ARCH_POSIX_LIBFUZZER=y
diff --git a/app/configs/fuzz_asan.conf b/app/configs/fuzz_asan.conf
index a4b504ea7617..81b76171cd09 100644
--- a/app/configs/fuzz_asan.conf
+++ b/app/configs/fuzz_asan.conf
@@ -1 +1,2 @@
 CONFIG_ASAN=y
+CONFIG_SYS_HEAP_SANITIZER_ASAN=y
diff --git a/app/configs/fuzz_ubsan.conf b/app/configs/fuzz_ubsan.conf
index ceae016bdc4f..b21e104ef677 100644
--- a/app/configs/fuzz_ubsan.conf
+++ b/app/configs/fuzz_ubsan.conf
@@ -1 +1,2 @@
 CONFIG_UBSAN=y
+CONFIG_SYS_HEAP_HARDENING_EXTREME=y