diff --git a/src/x49gpng/ui.c b/src/x49gpng/ui.c
index 7fce420..f7818f9 100644
--- a/src/x49gpng/ui.c
+++ b/src/x49gpng/ui.c
@@ -385,7 +385,7 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
      .rowbit = ( 1 << 1 ),
      .eint = 1,
      .bg_color = UI_COLOR_BLACK      },
-    {.label = "‘",
+    {.label = "'",
      .letter = "O",
      .left = "MTRW",
      .right = "EQW",
@@ -462,9 +462,9 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
      .rowbit = ( 1 << 2 ),
      .eint = 2,
      .bg_color = UI_COLOR_BLACK      },
-    {.label = "√X",
+    {.label = "√𝔁",
      .letter = "R",
-     .left = "x<sup>2</sup>",
+     .left = "𝔁<sup>2</sup>",
      .right = "<sup>x</sup>√y",
      .below = NULL,
      .color = UI_COLOR_WHITE,
@@ -541,7 +541,7 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
 
     {.label = "EEX",
      .letter = "V",
-     .left = "10<sup>x</sup>",
+     .left = "10<sup>𝔁</sup>",
      .right = "LOG",
      .below = NULL,
      .color = UI_COLOR_WHITE,
@@ -577,10 +577,10 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
      .rowbit = ( 1 << 3 ),
      .eint = 3,
      .bg_color = UI_COLOR_BLACK      },
-    {.label = "X",
+    {.label = "𝔁",
      .letter = "X",
      .left = "≤",
-     .right = "<",
+     .right = "&gt;",
      .below = NULL,
      .color = UI_COLOR_WHITE,
      .font_size = 12.0,
@@ -596,7 +596,7 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
      .rowbit = ( 1 << 3 ),
      .eint = 3,
      .bg_color = UI_COLOR_BLACK      },
-    {.label = "1/X",
+    {.label = "1/𝔁",
      .letter = "Y",
      .left = "≥",
      .right = ">",
@@ -675,7 +675,7 @@ static x49gp_ui_key_t ui_keys[ NB_KEYS ] = {
      .bg_color = UI_COLOR_BLACK      },
     {.label = "8",
      .letter = NULL,
-     .left = "EXP&LN",
+     .left = "EXP&amp;LN",
      .right = "TRIG",
      .below = NULL,
      .color = UI_COLOR_WHITE,