diff --git a/Libraries/LibJS/Runtime/Value.cpp b/Libraries/LibJS/Runtime/Value.cpp
index 78c42dee5d..8607423873 100644
--- a/Libraries/LibJS/Runtime/Value.cpp
+++ b/Libraries/LibJS/Runtime/Value.cpp
@@ -165,8 +165,7 @@ Value Value::to_number() const
     case Type::Number:
         return Value(m_value.as_double);
     case Type::String: {
-        // FIXME: Trim whitespace beforehand
-        auto& string = as_string().string();
+        auto string = as_string().string().trim_whitespace();
         if (string.is_empty())
             return Value(0);
         if (string == "Infinity" || string == "+Infinity")
diff --git a/Libraries/LibJS/Tests/to-number-basic.js b/Libraries/LibJS/Tests/to-number-basic.js
index 9a447fae32..f4659bea0d 100644
--- a/Libraries/LibJS/Tests/to-number-basic.js
+++ b/Libraries/LibJS/Tests/to-number-basic.js
@@ -35,6 +35,9 @@ try {
     assert(-"Infinity" === -Infinity);
     assert(-"+Infinity" === -Infinity);
     assert(-"-Infinity" === Infinity);
+    assert(+"  \r  \t \n " === 0);
+    assert(+"  \n  \t    Infinity   \r   " === Infinity);
+    assert(+"\r     \n1.23   \t\t\t  \n" === 1.23);
 
     assert(isNaN(+undefined));
     assert(isNaN(-undefined));