diff --git a/services/graphics-server/src/backend/betrusted.rs b/services/graphics-server/src/backend/betrusted.rs
index 09c44f9a1..7822be19e 100644
--- a/services/graphics-server/src/backend/betrusted.rs
+++ b/services/graphics-server/src/backend/betrusted.rs
@@ -5,8 +5,8 @@ use utralib::generated::*;
 use xous::MemoryRange;
 
 pub const FB_WIDTH_WORDS: usize = 11;
-pub const FB_WIDTH_PIXELS: usize = WIDTH;
-pub const FB_LINES: usize = LINES;
+pub const FB_WIDTH_PIXELS: usize = WIDTH as usize;
+pub const FB_LINES: usize = LINES as usize;
 pub const FB_SIZE: usize = FB_WIDTH_WORDS * FB_LINES; // 44 bytes by 536 lines
 const CONFIG_CLOCK_FREQUENCY: u32 = 100_000_000;