diff --git a/cowterm.c b/cowterm.c
index 42e65b2..d534d58 100644
--- a/cowterm.c
+++ b/cowterm.c
@@ -1070,6 +1070,10 @@ static int master_cb(int fd, void *data, Window window) {
     case '\b':
       if (cursor_x > 0) {
         cursor_x--;
+        terminal_buffer[cursor_y][cursor_x] = ' ';
+        color_buffer[cursor_y][cursor_x] = current_color;
+        attr_buffer[cursor_y][cursor_x] = current_attr;
+        bg_color_buffer[cursor_y][cursor_x] = current_bg_color;
         needs_refresh = 1;
       } else if (cursor_y > 0) {
         cursor_y--;
@@ -1082,16 +1086,18 @@ static int master_cb(int fd, void *data, Window window) {
     default:
       if (cursor_y >= term_rows || cursor_x >= term_cols)
         break;
-      terminal_buffer[cursor_y][cursor_x] = buf[i];
-      color_buffer[cursor_y][cursor_x] = current_color;
-      attr_buffer[cursor_y][cursor_x] = current_attr;
-      bg_color_buffer[cursor_y][cursor_x] = current_bg_color;
-      needs_refresh = 1;
-      if (++cursor_x >= term_cols) {
-        cursor_x = 0;
-        if (++cursor_y >= term_rows) {
-          scroll_region_up(1);
-          cursor_y = term_rows - 1;
+      if (buf[i] >= 32 && buf[i] <= 126) {
+        terminal_buffer[cursor_y][cursor_x] = buf[i];
+        color_buffer[cursor_y][cursor_x] = current_color;
+        attr_buffer[cursor_y][cursor_x] = current_attr;
+        bg_color_buffer[cursor_y][cursor_x] = current_bg_color;
+        needs_refresh = 1;
+        if (++cursor_x >= term_cols) {
+          cursor_x = 0;
+          if (++cursor_y >= term_rows) {
+            scroll_region_up(1);
+            cursor_y = term_rows - 1;
+          }
         }
       }
       break;