diff --git a/vlib/sync/sync_windows.c.v b/vlib/sync/sync_windows.c.v
index e5f53ca9fb..2a3e365b10 100644
--- a/vlib/sync/sync_windows.c.v
+++ b/vlib/sync/sync_windows.c.v
@@ -5,6 +5,8 @@ module sync
 
 import time
 
+#include <synchapi.h>
+
 fn C.InitializeConditionVariable(voidptr)
 fn C.WakeConditionVariable(voidptr)
 fn C.SleepConditionVariableSRW(voidptr, voidptr, u32, u32) int
diff --git a/vlib/v/gen/c/cheaders.v b/vlib/v/gen/c/cheaders.v
index e4aac76505..6a9329a4f3 100644
--- a/vlib/v/gen/c/cheaders.v
+++ b/vlib/v/gen/c/cheaders.v
@@ -280,14 +280,6 @@ $c_common_macros
 		#pragma comment(lib, "Dbghelp")
 
 		extern wchar_t **_wenviron;
-	#elif !defined(SRWLOCK_INIT)
-		// these seem to be missing on Windows tcc
-		typedef struct SRWLOCK { void* SRWLOCK; } SRWLOCK;
-		void InitializeSRWLock(void*);
-		void AcquireSRWLockShared(void*);
-		void AcquireSRWLockExclusive(void*);
-		void ReleaseSRWLockShared(void*);
-		void ReleaseSRWLockExclusive(void*);
 	#endif
 #else
 	#include <pthread.h>