diff --git a/Tests/LibWeb/Text/expected/script-src-set-after-insertion.txt b/Tests/LibWeb/Text/expected/script-src-set-after-insertion.txt
new file mode 100644
index 00000000000..7ef22e9a431
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/script-src-set-after-insertion.txt
@@ -0,0 +1 @@
+PASS
diff --git a/Tests/LibWeb/Text/input/script-src-set-after-insertion.html b/Tests/LibWeb/Text/input/script-src-set-after-insertion.html
new file mode 100644
index 00000000000..a30bc14a331
--- /dev/null
+++ b/Tests/LibWeb/Text/input/script-src-set-after-insertion.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<head></head>
+<script src="include.js"></script>
+<script>
+    asyncTest((done) => {
+        const el = document.createElement("script");
+        el.onload = () => {
+            done();
+        };
+        document.head.appendChild(el);
+        el.setAttribute("src", "script-src-set-after-insertion.js");
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/script-src-set-after-insertion.js b/Tests/LibWeb/Text/input/script-src-set-after-insertion.js
new file mode 100644
index 00000000000..ab333c9f6ae
--- /dev/null
+++ b/Tests/LibWeb/Text/input/script-src-set-after-insertion.js
@@ -0,0 +1 @@
+println("PASS");
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
index 1eca1aad78b..cfd6df6125e 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.cpp
@@ -58,6 +58,16 @@ void HTMLScriptElement::attribute_changed(FlyString const& name, Optional<String
         m_crossorigin = cors_setting_attribute_from_keyword(value);
     } else if (name == HTML::AttributeNames::referrerpolicy) {
         m_referrer_policy = ReferrerPolicy::from_string(value.value_or(""_string)).value_or(ReferrerPolicy::ReferrerPolicy::EmptyString);
+    } else if (name == HTML::AttributeNames::src) {
+        bool old_src_is_set = m_src_is_set;
+        m_src_is_set = value.has_value();
+        // https://html.spec.whatwg.org/multipage/scripting.html#script-processing-model
+        // When a script element el that is not parser-inserted experiences one of the events listed in the following list, the user agent must immediately prepare the script element el:
+        // - [...]
+        // - The script element is connected and has a src attribute set where previously the element had no such attribute.
+        if (!is_parser_inserted() && is_connected() && !old_src_is_set && m_src_is_set) {
+            prepare_script();
+        }
     }
 }
 
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h
index 68b410a53f4..537c94d0677 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLScriptElement.h
@@ -135,6 +135,8 @@ private:
     Optional<DOM::DocumentLoadEventDelayer> m_document_load_event_delayer;
 
     size_t m_source_line_number { 1 };
+
+    bool m_src_is_set = false;
 };
 
 }
