diff --git a/CMakeLists.txt b/CMakeLists.txt
index d165deb550494043ea38102f1e5b1c70d4e7b671..267bdfd94599ec35bad3bd0adb41265f2f2fe99b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -63,9 +63,13 @@ if(UNIX)
   # to be uncommented in CI
   # set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Werror")
 
-  # set C compiler
-  find_program(cc NAMES clang-18 clang REQUIRED)
-  set(CMAKE_C_COMPILER "${cc}" CACHE STRING "")
+  # Prefer clang-18 only when IVAS is built standalone
+  # don't override CMAKE_C_COMPILER if it's already set
+  if(CMAKE_SOURCE_DIR STREQUAL CMAKE_CURRENT_SOURCE_DIR AND NOT CMAKE_C_COMPILER)
+    # set C compiler
+    find_program(cc NAMES clang-18 clang REQUIRED)
+    set(CMAKE_C_COMPILER "${cc}" CACHE FILEPATH "")
+  endif()
 
   # CLANG
   if(CLANG)