diff --git a/src/gui_w32.c b/src/gui_w32.c
index 3914733..7bea58e 100644
--- a/src/gui_w32.c
+++ b/src/gui_w32.c
@@ -1455,10 +1455,16 @@
     HWND    hwnd = GetDesktopWindow();
     HDC	    hdc = GetWindowDC(hwnd);
     HFONT   hfntOld = SelectFont(hdc, (HFONT)font);
+    SIZE    size;
     TEXTMETRIC tm;
 
     GetTextMetrics(hdc, &tm);
-    gui.char_width = tm.tmAveCharWidth + tm.tmOverhang;
+    // GetTextMetrics() may not return the right value in tmAveCharWidth
+    // for some fonts.  Do our own average computation.
+    GetTextExtentPoint(hdc,
+	    "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz",
+	    52, &size);
+    gui.char_width = (size.cx / 26 + 1) / 2 + tm.tmOverhang;
 
     gui.char_height = tm.tmHeight + p_linespace;