diff --git a/src/cairo-mutex-list-private.h b/src/cairo-mutex-list-private.h
index af5cc0517..48f74f2c3 100644
--- a/src/cairo-mutex-list-private.h
+++ b/src/cairo-mutex-list-private.h
@@ -53,7 +53,6 @@ CAIRO_MUTEX_DECLARE (_cairo_ft_unscaled_font_map_mutex)
 
 #if CAIRO_HAS_WIN32_FONT
 CAIRO_MUTEX_DECLARE (_cairo_win32_font_face_mutex)
-CAIRO_MUTEX_DECLARE (_cairo_win32_font_dc_mutex)
 #endif
 
 #if CAIRO_HAS_XLIB_SURFACE
diff --git a/src/win32/cairo-dwrite-font.cpp b/src/win32/cairo-dwrite-font.cpp
index bf5191967..9f6d362b3 100644
--- a/src/win32/cairo-dwrite-font.cpp
+++ b/src/win32/cairo-dwrite-font.cpp
@@ -1496,12 +1496,15 @@ _cairo_dwrite_scaled_font_init_glyph_surface (cairo_dwrite_scaled_font_t *scaled
     switch (cairo_font_options_get_hint_style (&scaled_font->base.options)) {
         case CAIRO_HINT_STYLE_DEFAULT:
             grid_fit_mode = DWRITE_GRID_FIT_MODE_DEFAULT;
+            break;
         case CAIRO_HINT_STYLE_NONE:
             grid_fit_mode = DWRITE_GRID_FIT_MODE_DISABLED;
+            break;
         case CAIRO_HINT_STYLE_SLIGHT:
         case CAIRO_HINT_STYLE_MEDIUM:
         case CAIRO_HINT_STYLE_FULL:
             grid_fit_mode = DWRITE_GRID_FIT_MODE_ENABLED;
+            break;
     }
 
     cairo_subpixel_order_t subpixel_order;
diff --git a/src/win32/cairo-win32-font.c b/src/win32/cairo-win32-font.c
index 1412c8bbc..64c97e1b7 100644
--- a/src/win32/cairo-win32-font.c
+++ b/src/win32/cairo-win32-font.c
@@ -143,16 +143,14 @@ _cairo_win32_scaled_font_init_glyph_path (cairo_win32_scaled_font_t *scaled_font
 static HDC
 _get_global_font_dc (void)
 {
+    static cairo_atomic_once_t once = CAIRO_ATOMIC_ONCE_INIT;
     static DWORD hdc_tls_index;
     HDC hdc;
 
-    if (!hdc_tls_index) {
-	CAIRO_MUTEX_LOCK (_cairo_win32_font_dc_mutex);
-	if (!hdc_tls_index) {
-	    hdc_tls_index = TlsAlloc ();
-	    assert (hdc_tls_index != TLS_OUT_OF_INDEXES);
-	}
-	CAIRO_MUTEX_UNLOCK (_cairo_win32_font_dc_mutex);
+    if (!_cairo_atomic_init_once_enter (&once)) {
+        hdc_tls_index = TlsAlloc ();
+        assert (hdc_tls_index != TLS_OUT_OF_INDEXES);
+        _cairo_atomic_init_once_leave (&once);
     }
 
     hdc = TlsGetValue (hdc_tls_index);