diff --git a/dll/win32/kernel32/client/proc.c b/dll/win32/kernel32/client/proc.c
index 3b7d6f05ec5..a659101137a 100644
--- a/dll/win32/kernel32/client/proc.c
+++ b/dll/win32/kernel32/client/proc.c
@@ -445,12 +445,12 @@ BasepSxsCloseHandles(IN PBASE_MSG_SXS_HANDLES Handles)
     }
 }
 
+DECLSPEC_NORETURN
 VOID
 WINAPI
-BaseProcessStartup(PPROCESS_START_ROUTINE lpStartAddress)
+BaseProcessStartup(
+    _In_ PPROCESS_START_ROUTINE lpStartAddress)
 {
-    DPRINT("BaseProcessStartup(..) - setting up exception frame.\n");
-
     _SEH2_TRY
     {
         /* Set our Start Address */
diff --git a/dll/win32/kernel32/client/thread.c b/dll/win32/kernel32/client/thread.c
index 6d31a1b394d..0df088d510e 100644
--- a/dll/win32/kernel32/client/thread.c
+++ b/dll/win32/kernel32/client/thread.c
@@ -50,11 +50,12 @@ BasepNotifyCsrOfThread(IN HANDLE ThreadHandle,
     return STATUS_SUCCESS;
 }
 
-__declspec(noreturn)
+DECLSPEC_NORETURN
 VOID
 WINAPI
-BaseThreadStartup(IN LPTHREAD_START_ROUTINE lpStartAddress,
-                  IN LPVOID lpParameter)
+BaseThreadStartup(
+    _In_ LPTHREAD_START_ROUTINE lpStartAddress,
+    _In_ LPVOID lpParameter)
 {
     /* Attempt to call the Thread Start Address */
     _SEH2_TRY
@@ -67,7 +68,7 @@ BaseThreadStartup(IN LPTHREAD_START_ROUTINE lpStartAddress,
         }
 
         /* Get the exit code from the Thread Start */
-        ExitThread((lpStartAddress)((PVOID)lpParameter));
+        ExitThread(lpStartAddress(lpParameter));
     }
     _SEH2_EXCEPT(UnhandledExceptionFilter(_SEH2_GetExceptionInformation()))
     {
diff --git a/dll/win32/kernel32/include/kernel32.h b/dll/win32/kernel32/include/kernel32.h
index ef47d4d946c..c331e45f465 100644
--- a/dll/win32/kernel32/include/kernel32.h
+++ b/dll/win32/kernel32/include/kernel32.h
@@ -234,22 +234,25 @@ BasepProbeForDllManifest(
     OUT PVOID *ActCtx
 );
 
-__declspec(noreturn)
+DECLSPEC_NORETURN
 VOID
 WINAPI
-BaseThreadStartup(LPTHREAD_START_ROUTINE lpStartAddress,
-                  LPVOID lpParameter);
+BaseThreadStartup(
+    _In_ LPTHREAD_START_ROUTINE lpStartAddress,
+    _In_ LPVOID lpParameter);
 
-__declspec(noreturn)
+DECLSPEC_NORETURN
 VOID
 WINAPI
 BaseFiberStartup(VOID);
 
-typedef UINT (WINAPI *PPROCESS_START_ROUTINE)(VOID);
+typedef DWORD (WINAPI *PPROCESS_START_ROUTINE)(VOID);
 
+DECLSPEC_NORETURN
 VOID
 WINAPI
-BaseProcessStartup(PPROCESS_START_ROUTINE lpStartAddress);
+BaseProcessStartup(
+    _In_ PPROCESS_START_ROUTINE lpStartAddress);
 
 PVOID
 WINAPI