diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1f40aaf..5dfb6f4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -45,7 +45,10 @@ endif()
 string(TOUPPER "${CMAKE_BUILD_TYPE}" ENOKI_U_CMAKE_BUILD_TYPE)
 
 set(ENOKI_CXXFLAGS_BACKUP ${CMAKE_CXX_FLAGS})
-set(ENOKI_NATIVE_FLAGS "")
+
+if (NOT DEFINED ENOKI_NATIVE_FLAGS)
+  set(ENOKI_NATIVE_FLAGS "")
+endif()
 
 if (MSVC)
   set(ENOKI_ARCH_FLAGS_FILE archflags_win32.cpp)
@@ -64,11 +67,19 @@ endif()
 
 # Clang refuses -march=native on ARM machines
 if (${CMAKE_SYSTEM_PROCESSOR} MATCHES "armv7")
-  set(ENOKI_ARCH_FLAGS -march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4 -mfloat-abi=hard -mfp16-format=ieee)
-  set(ENOKI_NATIVE_FLAGS ${ENOKI_ARCH_FLAGS})
+  if (NOT DEFINED ENOKI_ARCH_FLAGS)
+    set(ENOKI_ARCH_FLAGS -march=armv7-a -mtune=cortex-a7 -mfpu=neon-vfpv4 -mfloat-abi=hard -mfp16-format=ieee)
+  endif()
+  if (NOT ENOKI_NATIVE_FLAGS)
+    set(ENOKI_NATIVE_FLAGS ${ENOKI_ARCH_FLAGS})
+  endif()
 elseif (${CMAKE_SYSTEM_PROCESSOR} MATCHES "aarch64")
-  set(ENOKI_ARCH_FLAGS -march=armv8-a+simd -mtune=cortex-a53)
-  set(ENOKI_NATIVE_FLAGS ${ENOKI_ARCH_FLAGS})
+  if (NOT DEFINED ENOKI_ARCH_FLAGS)
+    set(ENOKI_ARCH_FLAGS -march=armv8-a+simd -mtune=cortex-a53)
+  endif()
+  if (NOT ENOKI_NATIVE_FLAGS)
+    set(ENOKI_NATIVE_FLAGS ${ENOKI_ARCH_FLAGS})
+  endif()
 elseif (CMAKE_CXX_COMPILER MATCHES "/em\\+\\+(-[a-zA-Z0-9.])?$")
   # Emscripten
 else()