diff --git a/cmake/CompilerFlags.cmake b/cmake/CompilerFlags.cmake
index bf1e7f8eef..e187f5a150 100644
--- a/cmake/CompilerFlags.cmake
+++ b/cmake/CompilerFlags.cmake
@@ -25,6 +25,10 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "arm|ARM|arm64|ARM64|aarch64|AARCH64")
     # Windows ARM64: use /clang: prefix for clang-cl, skip for MSVC cl.exe subprojects
     # These flags are only understood by clang-cl, not MSVC cl.exe
     register_compiler_flags(/clang:-march=armv8-a+crc /clang:-mtune=ampere1)
+  elseif(ENABLE_BASELINE)
+    # Baseline ARM64: target ARMv8-A without optional extensions for older CPUs like Cortex-A53
+    # See https://github.com/oven-sh/bun/issues/26544
+    register_compiler_flags(-march=armv8-a -mtune=cortex-a53)
   else()
     register_compiler_flags(-march=armv8-a+crc -mtune=ampere1)
   endif()
diff --git a/cmake/Options.cmake b/cmake/Options.cmake
index 47e8e55457..8e8a32b7be 100644
--- a/cmake/Options.cmake
+++ b/cmake/Options.cmake
@@ -99,6 +99,9 @@ endif()
 
 if(ARCH STREQUAL "x64")
   optionx(ENABLE_BASELINE BOOL "If baseline features should be used for older CPUs (e.g. disables AVX, AVX2)" DEFAULT OFF)
+elseif(ARCH STREQUAL "aarch64" AND LINUX)
+  # ARM64 baseline only supported on Linux; macOS always uses apple_m1, Windows ARM64 doesn't support baseline yet
+  optionx(ENABLE_BASELINE BOOL "If baseline features should be used for older ARM64 CPUs (e.g. Cortex-A53)" DEFAULT OFF)
 endif()
 
 # Disabling logs by default for tests yields faster builds
diff --git a/cmake/targets/BuildBun.cmake b/cmake/targets/BuildBun.cmake
index 64536cc26b..ed440f1a96 100644
--- a/cmake/targets/BuildBun.cmake
+++ b/cmake/targets/BuildBun.cmake
@@ -683,6 +683,10 @@ if(CMAKE_SYSTEM_PROCESSOR MATCHES "arm|ARM|arm64|ARM64|aarch64|AARCH64")
     # Windows ARM64: use a specific CPU with NEON support
     # Zig running under x64 emulation would detect wrong CPU with "native"
     set(ZIG_CPU "cortex_a76")
+  elseif(ENABLE_BASELINE)
+    # Baseline ARM64: target Cortex-A35 for older CPUs like Cortex-A53
+    # See https://github.com/oven-sh/bun/issues/26544
+    set(ZIG_CPU "cortex_a35")
   else()
     set(ZIG_CPU "native")
   endif()
diff --git a/cmake/toolchains/linux-aarch64-baseline.cmake b/cmake/toolchains/linux-aarch64-baseline.cmake
new file mode 100644
index 0000000000..b9027a6519
--- /dev/null
+++ b/cmake/toolchains/linux-aarch64-baseline.cmake
@@ -0,0 +1,7 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR aarch64)
+set(ENABLE_BASELINE ON)
+set(ABI gnu)
+
+set(CMAKE_C_COMPILER_WORKS ON)
+set(CMAKE_CXX_COMPILER_WORKS ON)
diff --git a/cmake/toolchains/linux-aarch64-musl-baseline.cmake b/cmake/toolchains/linux-aarch64-musl-baseline.cmake
new file mode 100644
index 0000000000..5d0e89dbd1
--- /dev/null
+++ b/cmake/toolchains/linux-aarch64-musl-baseline.cmake
@@ -0,0 +1,7 @@
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR aarch64)
+set(ENABLE_BASELINE ON)
+set(ABI musl)
+
+set(CMAKE_C_COMPILER_WORKS ON)
+set(CMAKE_CXX_COMPILER_WORKS ON)