diff --git a/Source/exehead/Ui.c b/Source/exehead/Ui.c
index 2d89cf80..ee7989ea 100644
--- a/Source/exehead/Ui.c
+++ b/Source/exehead/Ui.c
@@ -982,7 +982,6 @@ static BOOL CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPar
   if (uMsg == WM_IN_UPDATEMSG || uMsg == WM_NOTIFY_START)
   {
     static char s[NSIS_MAX_STRLEN];
-    char *p;
     int error = 0;
     int available_set = 0;
     unsigned total, available = 0xFFFFFFFF;
@@ -992,9 +991,6 @@ static BOOL CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPar
       error = NSIS_INSTDIR_INVALID;
 
     mystrcpy(s,dir);
-    p=skip_root(s);
-    if (p)
-      *p=0;
 
     // Test for and use the GetDiskFreeSpaceEx API
     {
@@ -1020,6 +1016,12 @@ static BOOL CALLBACK DirProc(HWND hwndDlg, UINT uMsg, WPARAM wParam, LPARAM lPar
     {
       // GetDiskFreeSpaceEx is not available
       DWORD spc, bps, fc, tc;
+
+      // GetDiskFreeSpaceEx accepts any path, but GetDiskFreeSpace accepts only the root
+      char *p=skip_root(s);
+      if (p)
+        *p=0;
+
       if (GetDiskFreeSpace(s, &spc, &bps, &fc, &tc))
       {
         available = (int)MulDiv(bps * spc, fc, 1 << 10);