diff --git a/winsup/cygwin/init.cc b/winsup/cygwin/init.cc
index 56d4668..eb822a5 100644
--- a/winsup/cygwin/init.cc
+++ b/winsup/cygwin/init.cc
@@ -55,14 +55,23 @@ munge_threadfunc ()
 
   if (threadfunc_ix[0])
     {
-      char *threadfunc = ebp[threadfunc_ix[0]];
+      char *threadfunc0 = ebp[threadfunc_ix[0]];
+      char *threadfunc;
+      DWORD ret;
+
+      NtQueryInformationThread(GetCurrentThread(), ThreadQuerySetWin32StartAddress, &threadfunc, sizeof(threadfunc), &ret);
+
+      syscall_printf("threadfunc0 %p\n", threadfunc0);
+      syscall_printf("threadfunc %p\n", threadfunc);
+      syscall_printf("search_for %p\n", search_for);
       if (!search_for || threadfunc == search_for)
-	{
-	  search_for = NULL;
-	  for (i = 0; threadfunc_ix[i]; i++)
-	    ebp[threadfunc_ix[i]] = (char *) threadfunc_fe;
-	  TlsSetValue (_my_oldfunc, threadfunc);
-	}
+        {
+          search_for = NULL;
+          for (i = 0; threadfunc_ix[i]; i++)
+            if (ebp[threadfunc_ix[i]] == threadfunc)
+               ebp[threadfunc_ix[i]] = (char *) threadfunc_fe;
+          TlsSetValue (_my_oldfunc, threadfunc);
+        }
     }
 }
 
diff --git a/winsup/cygwin/ntdll.h b/winsup/cygwin/ntdll.h
index 13a131d..050e848 100644
--- a/winsup/cygwin/ntdll.h
+++ b/winsup/cygwin/ntdll.h
@@ -1162,7 +1162,8 @@ typedef enum _THREADINFOCLASS
 {
   ThreadBasicInformation = 0,
   ThreadTimes = 1,
-  ThreadImpersonationToken = 5
+  ThreadImpersonationToken = 5,
+  ThreadQuerySetWin32StartAddress = 9
 } THREADINFOCLASS, *PTHREADINFOCLASS;
 
 /* Checked on 64 bit. */