diff --git a/extern/mpg123/src/CMakeLists.txt b/extern/mpg123/src/CMakeLists.txt
index 019dd24ec..8bd9b0a35 100644
--- a/extern/mpg123/src/CMakeLists.txt
+++ b/extern/mpg123/src/CMakeLists.txt
@@ -495,6 +495,8 @@ target_compile_definitions(${TARGET} PRIVATE
 
 if(MSVC AND MACHINE MATCHES "x86|amd64" AND YASM_ASSEMBLER)
     list(TRANSFORM PLATFORM_DEFINITIONS PREPEND /D)
+    list(TRANSFORM PLATFORM_SOURCES PREPEND "${PROJECT_SOURCE_DIR}/src/")
+    message("PLATFORM_SOURCES: ${PLATFORM_SOURCES}")
     foreach(FILE ${PLATFORM_SOURCES})
         get_filename_component(FILENAME ${FILE} NAME)
         add_custom_command(