diff --git a/gfx-glyph/Cargo.toml b/gfx-glyph/Cargo.toml
index 839bc92..daa9ba1 100644
--- a/gfx-glyph/Cargo.toml
+++ b/gfx-glyph/Cargo.toml
@@ -19,7 +19,7 @@ log = "0.4"
 [dev-dependencies]
 env_logger = { version = "0.9", default-features = false }
 approx = "0.5"
-glutin = "0.27"
-old_school_gfx_glutin_ext = "0.27"
+glutin = "0.28"
+old_school_gfx_glutin_ext = "0.28"
 cgmath = "0.18"
 spin_sleep = "1"
diff --git a/gfx-glyph/src/lib.rs b/gfx-glyph/src/lib.rs
index 2f5e19a..66ac95e 100644
--- a/gfx-glyph/src/lib.rs
+++ b/gfx-glyph/src/lib.rs
@@ -360,7 +360,7 @@ where
     pub(crate) fn draw<C, CV, DV>(
         &mut self,
         transform: [[f32; 4]; 4],
-        mut encoder: &mut gfx::Encoder<R, C>,
+        encoder: &mut gfx::Encoder<R, C>,
         target: &CV,
         depth_target: Option<&DV>,
     ) -> Result<(), String>
@@ -378,7 +378,7 @@ where
                 |rect, tex_data| {
                     let offset = [rect.min[0] as u16, rect.min[1] as u16];
                     let size = [rect.width() as u16, rect.height() as u16];
-                    update_texture(&mut encoder, &tex, offset, size, tex_data);
+                    update_texture(encoder, &tex, offset, size, tex_data);
                 },
                 to_vertex,
             );
diff --git a/glyph-brush/Cargo.toml b/glyph-brush/Cargo.toml
index 5c57e95..4fb42c0 100644
--- a/glyph-brush/Cargo.toml
+++ b/glyph-brush/Cargo.toml
@@ -26,7 +26,7 @@ features = ["std"]
 env_logger = { version = "0.9", default-features = false }
 once_cell = "1.3"
 gl = "0.14"
-glutin = "0.27"
+glutin = "0.28"
 spin_sleep = "1"
 approx = "0.5"
 criterion = "0.3"