diff --git a/font/src/darwin/mod.rs b/font/src/darwin/mod.rs
index ca784ae..0e694f1 100644
--- a/font/src/darwin/mod.rs
+++ b/font/src/darwin/mod.rs
@@ -430,21 +430,17 @@ impl Font {
         let leading = self.ct_font.leading() as f64;
         let line_height = (ascent + descent + leading + 0.5).floor();
 
-        // Strikeout and underline metrics
-        // CoreText doesn't provide strikeout so we provide our own
-        let underline_position =
-            (self.ct_font.underline_position() - descent)
-            .round() as f32;
-        let underline_thickness = self.ct_font.underline_thickness()
-            .round()
-            .max(1.) as f32;
-        let strikeout_position = (line_height as f32 / 2. - descent as f32).round();
+        // Strikeout and underline metrics.
+        // CoreText doesn't provide strikeout so we provide our own.
+        let underline_position = (self.ct_font.underline_position() - descent) as f32;
+        let underline_thickness = self.ct_font.underline_thickness() as f32;
+        let strikeout_position = (line_height / 2. - descent) as f32;
         let strikeout_thickness = underline_thickness;
 
         Metrics {
             average_advance,
             line_height,
-            descent: -(self.ct_font.descent() as f32),
+            descent: -(descent as f32),
             underline_position,
             underline_thickness,
             strikeout_position,
diff --git a/font/src/ft/mod.rs b/font/src/ft/mod.rs
index 03e8bb3..1d37529 100644
--- a/font/src/ft/mod.rs
+++ b/font/src/ft/mod.rs
@@ -97,22 +97,22 @@ impl ::Rasterize for FreeTypeRasterizer {
 
         // Get underline position and thickness in device pixels
         let x_scale = full.size_metrics.x_scale as f32 / 65536.0;
-        let underline_position =
-            (f32::from(face.ft_face.underline_position()) * x_scale / 64.).round();
-        let underline_thickness =
-            (f32::from(face.ft_face.underline_thickness()) * x_scale / 64.)
-            .round()
-            .max(1.);
+        let mut underline_position = f32::from(face.ft_face.underline_position()) * x_scale / 64.;
+        let mut underline_thickness = f32::from(face.ft_face.underline_thickness()) * x_scale / 64.;
+
+        // Fallback for bitmap fonts which do not provide underline metrics
+        if underline_position == 0. {
+            underline_thickness = (descent / 5.).round();
+            underline_position = descent / 2.;
+        }
 
         // Get strikeout position and thickness in device pixels
         let (strikeout_position, strikeout_thickness) =
             match TrueTypeOS2Table::from_face(&mut face.ft_face.clone())
         {
             Some(os2) => {
-                let strikeout_position =
-                    (f32::from(os2.y_strikeout_position()) * x_scale / 64.).round();
-                let strikeout_thickness =
-                    (f32::from(os2.y_strikeout_size()) * x_scale / 64.).round();
+                let strikeout_position = f32::from(os2.y_strikeout_position()) * x_scale / 64.;
+                let strikeout_thickness = f32::from(os2.y_strikeout_size()) * x_scale / 64.;
                 (strikeout_position, strikeout_thickness)
             },
             _ => {
diff --git a/font/src/rusttype/mod.rs b/font/src/rusttype/mod.rs
index 2d28a8b..bd4b8df 100644
--- a/font/src/rusttype/mod.rs
+++ b/font/src/rusttype/mod.rs
@@ -38,11 +38,11 @@ impl crate::Rasterize for RustTypeRasterizer {
         let average_advance = f64::from(hmetrics.advance_width);
         let descent = vmetrics.descent;
 
-        // Strikeout and underline metrics
-        // RustType doesn't support these, so we make up our own
+        // Strikeout and underline metrics.
+        // RustType doesn't support these, so we make up our own.
         let thickness = (descent / 5.).round();
-        let underline_position = descent / 2. + thickness / 2.;
-        let strikeout_position = (line_height as f32 / 2. - descent).round();
+        let underline_position = descent / 2.;
+        let strikeout_position = line_height as f32 / 2. - descent;
 
         Ok(Metrics {
             descent,
diff --git a/src/renderer/lines.rs b/src/renderer/lines.rs
index 99d1f28..3c250ca 100644
--- a/src/renderer/lines.rs
+++ b/src/renderer/lines.rs
@@ -122,12 +122,15 @@ fn create_rect(
     let end_x = (end.column.0 + 1) as f32 * size.cell_width;
     let width = end_x - start_x;
 
-    let (position, height) = match flag {
+    let (position, mut height) = match flag {
         Flags::UNDERLINE => (metrics.underline_position, metrics.underline_thickness),
         Flags::STRIKEOUT => (metrics.strikeout_position, metrics.strikeout_thickness),
         _ => unimplemented!("Invalid flag for cell line drawing specified"),
     };
 
+    // Make sure lines are always visible
+    height = height.max(1.);
+
     let cell_bottom = (start.line.0 as f32 + 1.) * size.cell_height;
     let baseline = cell_bottom + metrics.descent;
 
@@ -139,9 +142,9 @@ fn create_rect(
 
     let rect = Rect::new(
         start_x + size.padding_x,
-        y + size.padding_y,
+        y.round() + size.padding_y,
         width,
-        height,
+        height.round(),
     );
 
     (rect, start.fg)