diff --git a/src/microsoft/clc/clc_helpers.cpp b/src/microsoft/clc/clc_helpers.cpp
index 912a2a9e9e5..3af2c87d6b7 100644
--- a/src/microsoft/clc/clc_helpers.cpp
+++ b/src/microsoft/clc/clc_helpers.cpp
@@ -803,12 +803,12 @@ clc_compile_to_llvm_module(const struct clc_compile_args *args,
 
       ::llvm::sys::path::append(system_header_path, "opencl-c.h");
       c->getPreprocessorOpts().addRemappedFile(system_header_path.str(),
-         ::llvm::MemoryBuffer::getMemBuffer(llvm::StringRef(opencl_c_source, _countof(opencl_c_source) - 1)).release());
+         ::llvm::MemoryBuffer::getMemBuffer(llvm::StringRef(opencl_c_source, ARRAY_SIZE(opencl_c_source) - 1)).release());
 
       ::llvm::sys::path::remove_filename(system_header_path);
       ::llvm::sys::path::append(system_header_path, "opencl-c-base.h");
       c->getPreprocessorOpts().addRemappedFile(system_header_path.str(),
-         ::llvm::MemoryBuffer::getMemBuffer(llvm::StringRef(opencl_c_base_source, _countof(opencl_c_base_source) - 1)).release());
+         ::llvm::MemoryBuffer::getMemBuffer(llvm::StringRef(opencl_c_base_source, ARRAY_SIZE(opencl_c_base_source) - 1)).release());
    }
 
    if (args->num_headers) {