diff --git a/dlls/kernel32/environ.c b/dlls/kernel32/environ.c
index 99bf706e95e..0fa7596f04a 100644
--- a/dlls/kernel32/environ.c
+++ b/dlls/kernel32/environ.c
@@ -139,7 +139,21 @@ LPSTR WINAPI GetEnvironmentStringsA(void)
  */
 LPWSTR WINAPI GetEnvironmentStringsW(void)
 {
-    return NtCurrentTeb()->Peb->ProcessParameters->Environment;
+    LPWSTR ret, ptrW;
+    unsigned len;
+
+    RtlAcquirePebLock();
+
+    ptrW = NtCurrentTeb()->Peb->ProcessParameters->Environment;
+    while (*ptrW) ptrW += strlenW(ptrW) + 1;
+    ptrW++;
+
+    len = (ptrW - NtCurrentTeb()->Peb->ProcessParameters->Environment) * sizeof(WCHAR);
+    ret = HeapAlloc(GetProcessHeap(), 0, len);
+    if (ret) memcpy(ret, NtCurrentTeb()->Peb->ProcessParameters->Environment, len);
+
+    RtlReleasePebLock();
+    return ret;
 }
 
 
@@ -157,7 +171,7 @@ BOOL WINAPI FreeEnvironmentStringsA( LPSTR ptr )
  */
 BOOL WINAPI FreeEnvironmentStringsW( LPWSTR ptr )
 {
-    return TRUE;
+    return HeapFree( GetProcessHeap(), 0, ptr );
 }
 
 
diff --git a/dlls/kernel32/tests/environ.c b/dlls/kernel32/tests/environ.c
index f8452be2ee6..4249ea7ebea 100644
--- a/dlls/kernel32/tests/environ.c
+++ b/dlls/kernel32/tests/environ.c
@@ -554,6 +554,20 @@ static void test_GetComputerNameExW(void)
     HeapFree(GetProcessHeap(), 0, nameW);
 }
 
+static void test_GetEnvironmentStringsW(void)
+{
+    PWCHAR env1;
+    PWCHAR env2;
+
+    env1 = GetEnvironmentStringsW();
+    env2 = GetEnvironmentStringsW();
+    ok(env1 != env2 ||
+       broken(env1 == env2), /* NT <= 5.1 */
+       "should return different copies\n");
+    FreeEnvironmentStringsW(env1);
+    FreeEnvironmentStringsW(env2);
+}
+
 START_TEST(environ)
 {
     init_functionpointers();
@@ -565,4 +579,5 @@ START_TEST(environ)
     test_GetComputerName();
     test_GetComputerNameExA();
     test_GetComputerNameExW();
+    test_GetEnvironmentStringsW();
 }