diff --git a/VocieProcess/CMakeLists.txt b/VocieProcess/CMakeLists.txt
index 1d3a13d..941fc33 100644
--- a/VocieProcess/CMakeLists.txt
+++ b/VocieProcess/CMakeLists.txt
@@ -44,7 +44,7 @@ add_library(VocieProcess
     rtc_base/string_utils.h rtc_base/string_utils.cc
     rtc_base/system_time.h rtc_base/system_time.cc
     rtc_base/time_utils.h rtc_base/time_utils.cc
-    rtc_base/win32.h rtc_base/win32.cc
+    $<$<PLATFORM_ID:Windows>:rtc_base/win32.h rtc_base/win32.cc>
 
     rtc_base/containers/flat_tree.h rtc_base/containers/flat_tree.cc
 
@@ -123,11 +123,12 @@ add_library(VocieProcess
 )
 
 target_compile_definitions(VocieProcess
-    PRIVATE WEBRTC_WIN
     PRIVATE NOMINMAX # <windows.h>
     PRIVATE RTC_DISABLE_LOGGING
     PRIVATE RTC_METRICS_ENABLED=0
     PRIVATE WEBRTC_APM_DEBUG_DUMP=0
+    $<$<PLATFORM_ID:Windows>:WEBRTC_WIN>
+    $<$<PLATFORM_ID:Linux>:WEBRTC_POSIX WEBRTC_LINUX>
 )
 
 target_include_directories(VocieProcess