diff --git a/boa/src/builtins/regexp/mod.rs b/boa/src/builtins/regexp/mod.rs
index 62defc8d09..2018d6bb89 100644
--- a/boa/src/builtins/regexp/mod.rs
+++ b/boa/src/builtins/regexp/mod.rs
@@ -211,13 +211,10 @@ impl RegExp {
         let arg = args.get(0).ok_or_else(Value::undefined)?;
 
         let (regex_body, mut regex_flags) = match arg {
-            Value::String(ref body) => {
-                // first argument is a string -> use it as regex pattern
-                (
-                    body.to_string().into_boxed_str(),
-                    String::new().into_boxed_str(),
-                )
-            }
+            Value::Undefined => (
+                String::new().into_boxed_str(),
+                String::new().into_boxed_str(),
+            ),
             Value::Object(ref obj) => {
                 let obj = obj.borrow();
                 if let Some(regex) = obj.as_regexp() {
@@ -225,12 +222,15 @@ impl RegExp {
                     (regex.original_source.clone(), regex.original_flags.clone())
                 } else {
                     (
-                        String::new().into_boxed_str(),
+                        arg.to_string(ctx)?.to_string().into_boxed_str(),
                         String::new().into_boxed_str(),
                     )
                 }
             }
-            _ => return Err(Value::undefined()),
+            _ => (
+                arg.to_string(ctx)?.to_string().into_boxed_str(),
+                String::new().into_boxed_str(),
+            ),
         };
         // if a second argument is given and it's a string, use it as flags
         if let Some(Value::String(flags)) = args.get(1) {
diff --git a/boa/src/builtins/string/mod.rs b/boa/src/builtins/string/mod.rs
index 2cd948b01e..cbe2fb28dc 100644
--- a/boa/src/builtins/string/mod.rs
+++ b/boa/src/builtins/string/mod.rs
@@ -872,12 +872,11 @@ impl String {
             // a. Let matcher be ? GetMethod(regexp, @@match).
             // b. If matcher is not undefined, then
             if let Some(matcher) = regexp
-                .as_object()
-                .unwrap_or_default()
-                .get_method(context, "match")?
+                .to_object(context)?
+                .get_method(context, WellKnownSymbols::match_())?
             {
                 // i. Return ? Call(matcher, regexp, « O »).
-                return matcher.call(&regexp, &[object.clone()], context);
+                return matcher.call(&regexp, &[this.clone()], context);
             }
         }