diff --git a/kitty/fonts.py b/kitty/fonts.py
index 135d4cfb5..1f3c998f6 100644
--- a/kitty/fonts.py
+++ b/kitty/fonts.py
@@ -42,7 +42,7 @@ def get_font(query, bold, italic):
 def find_font_for_character(family, char, bold=False, italic=False):
     q = escape_family_name(family) + ':charset={}'.format(hex(ord(char[0]))[2:])
     if bold:
-        q += ':bold=200'
+        q += ':weight=200'
     if italic:
         q += ':slant=100'
     return get_font(q, bold, italic)
@@ -52,7 +52,7 @@ def find_font_for_character(family, char, bold=False, italic=False):
 def get_font_information(q, bold=False, italic=False):
     q = escape_family_name(q)
     if bold:
-        q += ':bold=200'
+        q += ':weight=200'
     if italic:
         q += ':slant=100'
     return get_font(q, bold, italic)
diff --git a/kitty/shaders.py b/kitty/shaders.py
index c673ba41f..686016775 100644
--- a/kitty/shaders.py
+++ b/kitty/shaders.py
@@ -138,7 +138,7 @@ class Sprites:
         except KeyError:
             pass
         text, attrs = key
-        bold, italic = attrs & BOLD_MASK, attrs & ITALIC_MASK
+        bold, italic = bool(attrs & BOLD_MASK), bool(attrs & ITALIC_MASK)
         first, second = render_cell(text, bold, italic)
         self.first_cell_cache[key] = first = self.add_sprite(first)
         if second is not None: