diff --git a/dlls/user32/sysparams.c b/dlls/user32/sysparams.c
index 5029902bdd7..175753caa40 100644
--- a/dlls/user32/sysparams.c
+++ b/dlls/user32/sysparams.c
@@ -2419,6 +2419,7 @@ INT WINAPI GetSystemMetrics( INT index )
     case SM_RESERVED4:
         return 0;
     case SM_CXMIN:
+        ncm.cbSize = sizeof(ncm);
         SystemParametersInfoW( SPI_GETNONCLIENTMETRICS, 0, &ncm, 0 );
         get_text_metr_size( get_display_dc(), &ncm.lfCaptionFont, NULL, &ret );
         return 3 * ncm.iCaptionWidth + ncm.iCaptionHeight + 4 * ret + 2 * GetSystemMetrics(SM_CXFRAME) + 4;
@@ -2428,6 +2429,7 @@ INT WINAPI GetSystemMetrics( INT index )
         get_entry( &entry_CAPTIONWIDTH, 0, &ret );
         return max( 8, ret );
     case SM_CYSIZE:
+        ncm.cbSize = sizeof(ncm);
         SystemParametersInfoW( SPI_GETNONCLIENTMETRICS, 0, &ncm, 0 );
         return ncm.iCaptionHeight;
     case SM_CXFRAME:
@@ -2486,12 +2488,14 @@ INT WINAPI GetSystemMetrics( INT index )
         get_entry( &entry_SMCAPTIONWIDTH, 0, &ret );
         return ret;
     case SM_CYSMSIZE:
+        ncm.cbSize = sizeof(ncm);
         SystemParametersInfoW( SPI_GETNONCLIENTMETRICS, 0, &ncm, 0 );
         return ncm.iSmCaptionHeight;
     case SM_CXMENUSIZE:
         get_entry( &entry_MENUWIDTH, 0, &ret );
         return ret;
     case SM_CYMENUSIZE:
+        ncm.cbSize = sizeof(ncm);
         SystemParametersInfoW( SPI_GETNONCLIENTMETRICS, 0, &ncm, 0 );
         return ncm.iMenuHeight;
     case SM_ARRANGE:
@@ -2529,6 +2533,7 @@ INT WINAPI GetSystemMetrics( INT index )
     case SM_CYMENUCHECK:
     {
         TEXTMETRICW tm;
+        ncm.cbSize = sizeof(ncm);
         SystemParametersInfoW( SPI_GETNONCLIENTMETRICS, 0, &ncm, 0 );
         get_text_metr_size( get_display_dc(), &ncm.lfMenuFont, &tm, NULL);
         return tm.tmHeight <= 0 ? 13 : ((tm.tmHeight + tm.tmExternalLeading + 1) / 2) * 2 - 1;