diff --git a/dlls/ntdll/env.c b/dlls/ntdll/env.c
index fdd5d4f8960..417efb6073c 100644
--- a/dlls/ntdll/env.c
+++ b/dlls/ntdll/env.c
@@ -452,6 +452,7 @@ NTSTATUS WINAPI RtlCreateProcessParametersEx( RTL_USER_PROCESS_PARAMETERS **resu
     static const UNICODE_STRING empty_str = { 0, sizeof(empty), empty };
     static const UNICODE_STRING null_str = { 0, 0, NULL };
 
+    UNICODE_STRING curdir;
     const RTL_USER_PROCESS_PARAMETERS *cur_params;
     SIZE_T size, env_size, total_size;
     void *ptr;
@@ -464,10 +465,13 @@ NTSTATUS WINAPI RtlCreateProcessParametersEx( RTL_USER_PROCESS_PARAMETERS **resu
     if (!CurrentDirectoryName)
     {
         if (NtCurrentTeb()->Tib.SubSystemTib)  /* FIXME: hack */
-            CurrentDirectoryName = &((WIN16_SUBSYSTEM_TIB *)NtCurrentTeb()->Tib.SubSystemTib)->curdir.DosPath;
+            curdir = ((WIN16_SUBSYSTEM_TIB *)NtCurrentTeb()->Tib.SubSystemTib)->curdir.DosPath;
         else
-            CurrentDirectoryName = &cur_params->CurrentDirectory.DosPath;
+            curdir = cur_params->CurrentDirectory.DosPath;
     }
+    else curdir = *CurrentDirectoryName;
+    curdir.MaximumLength = MAX_PATH * sizeof(WCHAR);
+
     if (!CommandLine) CommandLine = ImagePathName;
     if (!Environment) Environment = cur_params->Environment;
     if (!WindowTitle) WindowTitle = &empty_str;
@@ -503,7 +507,7 @@ NTSTATUS WINAPI RtlCreateProcessParametersEx( RTL_USER_PROCESS_PARAMETERS **resu
         /* all other fields are zero */
 
         ptr = params + 1;
-        append_unicode_string( &ptr, CurrentDirectoryName, &params->CurrentDirectory.DosPath );
+        append_unicode_string( &ptr, &curdir, &params->CurrentDirectory.DosPath );
         append_unicode_string( &ptr, DllPath, &params->DllPath );
         append_unicode_string( &ptr, ImagePathName, &params->ImagePathName );
         append_unicode_string( &ptr, CommandLine, &params->CommandLine );
diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c
index 9b23fbf6d13..c4e02dacb1d 100644
--- a/dlls/ntdll/thread.c
+++ b/dlls/ntdll/thread.c
@@ -68,7 +68,7 @@ struct startup_info
 static PEB *peb;
 static PEB_LDR_DATA ldr;
 static RTL_USER_PROCESS_PARAMETERS params;  /* default parameters if no parent */
-static WCHAR current_dir[MAX_NT_PATH_LENGTH];
+static WCHAR current_dir[MAX_PATH];
 static RTL_BITMAP tls_bitmap;
 static RTL_BITMAP tls_expansion_bitmap;
 static RTL_BITMAP fls_bitmap;
@@ -130,7 +130,7 @@ static NTSTATUS init_user_process_params( SIZE_T data_size )
     if (status != STATUS_SUCCESS) goto done;
 
     size = sizeof(*params);
-    size += MAX_NT_PATH_LENGTH * sizeof(WCHAR);
+    size += sizeof(current_dir);
     size += info->dllpath_len + sizeof(WCHAR);
     size += info->imagepath_len + sizeof(WCHAR);
     size += info->cmdline_len + sizeof(WCHAR);
@@ -169,8 +169,8 @@ static NTSTATUS init_user_process_params( SIZE_T data_size )
 
     /* current directory needs more space */
     get_unicode_string( &params->CurrentDirectory.DosPath, &src, &dst, info->curdir_len );
-    params->CurrentDirectory.DosPath.MaximumLength = MAX_NT_PATH_LENGTH * sizeof(WCHAR);
-    dst = (WCHAR *)(params + 1) + MAX_NT_PATH_LENGTH;
+    params->CurrentDirectory.DosPath.MaximumLength = sizeof(current_dir);
+    dst = (WCHAR *)(params + 1) + ARRAY_SIZE(current_dir);
 
     get_unicode_string( &params->DllPath, &src, &dst, info->dllpath_len );
     get_unicode_string( &params->ImagePathName, &src, &dst, info->imagepath_len );