diff --git a/INSTALL.md b/INSTALL.md
index 9208e63f..9bd6996f 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -37,6 +37,7 @@ Options
 |------|-------|-------|
 |AIS\_USE\_CLANG\_TIDY|OFF|Run the `clang-tidy` tool|
 |AIS\_USE\_IWYU|OFF|Run the `include-what-you-use` tool|
+|AIS\_WARN\_UNSAFE\_BUFFER\_OPS|ON|Scan code for unsafe buffer operations (clang only, OFF for others)|
 |BUILD\_AIS\_DOCS|OFF|Build API documentation (requires Doxygen)|
 |BUILD\_AISCP|ON|Build `aiscp` example program (OFF if no hipFile)|
 |BUILD\_CODE\_COVERAGE|OFF|Generate code coverage information when tests are run|
diff --git a/cmake/AISClangSafeBuffers.cmake b/cmake/AISClangSafeBuffers.cmake
index a8281e34..3994f289 100644
--- a/cmake/AISClangSafeBuffers.cmake
+++ b/cmake/AISClangSafeBuffers.cmake
@@ -9,7 +9,13 @@
 #
 # Fixing this cleanly requires C++20, so it's an option for now
 #-----------------------------------------------------------------------------
-option(AIS_WARN_UNSAFE_BUFFER_OPS "Warn about unsafe buffer operations (llvm C++ only)" OFF)
+if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    set(USE_UBO ON)
+else()
+    set(USE_UBO OFF)
+endif()
+option(AIS_WARN_UNSAFE_BUFFER_OPS "Warn about unsafe buffer operations (llvm C++ only)" ${USE_UBO})
+
 if(AIS_WARN_UNSAFE_BUFFER_OPS)
     if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
         set(AIS_CLANG_WARNING_FLAGS
@@ -17,5 +23,7 @@ if(AIS_WARN_UNSAFE_BUFFER_OPS)
             -fsafe-buffer-usage-suggestions
             ${AIS_CLANG_WARNING_FLAGS}
         )
+    else()
+        message(FATAL_ERROR "Unsafe buffer warnings are only useful for clang/llvm")
     endif()
 endif()