diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 08ad66b49..b1b41abd4 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -1,3 +1,8 @@
+if(WIN32)
+    add_compile_options("$<$<CXX_COMPILER_ID:MSVC>:/source-charset:utf-8>")
+    add_compile_options("$<$<C_COMPILER_ID:MSVC>:/source-charset:utf-8>")
+endif()
+
 function(llama_test target)
     include(CMakeParseArguments)
     set(options)