diff --git a/reactos/lib/msvcrt/stdlib/putenv.c b/reactos/lib/msvcrt/stdlib/putenv.c
index bdd97a0c077..de3cab4444a 100644
--- a/reactos/lib/msvcrt/stdlib/putenv.c
+++ b/reactos/lib/msvcrt/stdlib/putenv.c
@@ -3,10 +3,13 @@
 #include <msvcrt/string.h>
 
 
+extern int BlockEnvToEnviron(); // defined in misc/dllmain.c
+
 int _putenv(const char *val)
 {
   char buffer[1024];
   char *epos;
+  int res;
 
   strcpy(buffer,val);
   epos = strchr(buffer, '=');
@@ -15,13 +18,16 @@ int _putenv(const char *val)
 
   *epos = 0;
 
-  return SetEnvironmentVariableA(buffer,epos+1);
+  res = SetEnvironmentVariableA(buffer,epos+1);
+  if (BlockEnvToEnviron() ) return 0;
+  return  res;
 }
 
 int _wputenv(const wchar_t *val)
 {
   wchar_t buffer[1024];
   wchar_t *epos;
+  int res;
 
   wcscpy(buffer,val);
   epos = wcschr(buffer, L'=');
@@ -30,5 +36,7 @@ int _wputenv(const wchar_t *val)
 
   *epos = 0;
 
-  return SetEnvironmentVariableW(buffer,epos+1);
+  res = SetEnvironmentVariableW(buffer,epos+1);
+  if (BlockEnvToEnviron() ) return 0;
+  return  res;
 }