diff --git a/st7565-lcd/raspilcd.adb b/st7565-lcd/raspilcd.adb
index e1e2e66..89774da 100644
--- a/st7565-lcd/raspilcd.adb
+++ b/st7565-lcd/raspilcd.adb
@@ -52,7 +52,7 @@ package body RaspiLcd is
         lcd_set_page(page => ypos, column => xpos);
         -- write one 5x7 char
         for index in 0..4 loop
-            lcd_transfer_data(value => font_5x7(character'pos(data) - 32)(index), si => true);
+            lcd_transfer_data(value => font_5x7(character'pos(data))(index), si => true);
         end loop;
         -- one free column between chars
         lcd_transfer_data(value => 16#00#, si => true);
diff --git a/st7565-lcd/raspilcd.ads b/st7565-lcd/raspilcd.ads
index 8234b7e..d1797e4 100644
--- a/st7565-lcd/raspilcd.ads
+++ b/st7565-lcd/raspilcd.ads
@@ -14,7 +14,7 @@ package RaspiLcd is
 
 
     -- character set
-    font_5x7 : constant byte_byte_array := (
+    font_5x7 : constant byte_byte_array (32 .. 126) := (
         ( 16#00#, 16#00#, 16#00#, 16#00#, 16#00# ),  --   - 16#20 - 32
         ( 16#00#, 16#00#, 16#5f#, 16#00#, 16#00# ),  -- ! - 16#21 - 33
         ( 16#00#, 16#07#, 16#00#, 16#07#, 16#00# ),  -- " - 16#22 - 34