diff --git a/servo/components/style/values/specified/font.rs b/servo/components/style/values/specified/font.rs
index ecc2a78a4c3e..fb59a53cef04 100644
--- a/servo/components/style/values/specified/font.rs
+++ b/servo/components/style/values/specified/font.rs
@@ -925,7 +925,7 @@ impl FontSize {
// If the parent font was keyword-derived, this is too.
// Tack the % onto the factor
info = compose_keyword(pc.0);
- base_size.resolve(context) * pc.0
+ (base_size.resolve(context) * pc.0).normalized()
},
FontSize::Length(LengthPercentage::Calc(ref calc)) => {
let calc = calc.to_computed_value_zoomed(context, base_size);
diff --git a/servo/components/style/values/specified/length.rs b/servo/components/style/values/specified/length.rs
index 4fc841aea932..2eafa9fbd605 100644
--- a/servo/components/style/values/specified/length.rs
+++ b/servo/components/style/values/specified/length.rs
@@ -135,7 +135,7 @@ impl FontRelativeLength {
base_size: FontBaseSize,
) -> computed::Length {
let (reference_size, length) = self.reference_font_size_and_length(context, base_size);
- reference_size * length
+ (reference_size * length).normalized()
}
/// Return reference font size.
diff --git a/testing/web-platform/tests/css/css-fonts/infinite-size-crash.html b/testing/web-platform/tests/css/css-fonts/infinite-size-crash.html
new file mode 100644
index 000000000000..d44cf4a37e26
--- /dev/null
+++ b/testing/web-platform/tests/css/css-fonts/infinite-size-crash.html
@@ -0,0 +1,20 @@
+
+
+
+
+
+
+
+
+