diff --git a/Userland/Libraries/LibWeb/SVG/AttributeParser.cpp b/Userland/Libraries/LibWeb/SVG/AttributeParser.cpp
index 826e4a9d51..9649eb38e7 100644
--- a/Userland/Libraries/LibWeb/SVG/AttributeParser.cpp
+++ b/Userland/Libraries/LibWeb/SVG/AttributeParser.cpp
@@ -66,7 +66,7 @@ Optional<float> AttributeParser::parse_length(StringView input)
     return {};
 }
 
-float NumberPercentage::resolve_relative_to(float length)
+float NumberPercentage::resolve_relative_to(float length) const
 {
     if (!m_is_percentage)
         return m_value;
diff --git a/Userland/Libraries/LibWeb/SVG/AttributeParser.h b/Userland/Libraries/LibWeb/SVG/AttributeParser.h
index 1e7578cdb2..2fee747f69 100644
--- a/Userland/Libraries/LibWeb/SVG/AttributeParser.h
+++ b/Userland/Libraries/LibWeb/SVG/AttributeParser.h
@@ -111,9 +111,9 @@ public:
         return NumberPercentage(value, false);
     }
 
-    float resolve_relative_to(float length);
+    float resolve_relative_to(float length) const;
 
-    float value() { return m_value; }
+    float value() const { return m_value; }
 
 private:
     float m_value;