diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index c7f9d41310..e29d0d6e5e 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -47,6 +47,7 @@ set(SOURCES
     CSS/Parser/ComponentValue.cpp
     CSS/Parser/Function.cpp
     CSS/Parser/Parser.cpp
+    CSS/Parser/StyleBlockRule.cpp
     CSS/Parser/StyleRules.cpp
     CSS/Parser/Token.cpp
     CSS/Parser/Tokenizer.cpp
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.cpp b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.cpp
new file mode 100644
index 0000000000..dc7f8d365a
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.cpp
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2020-2021, the SerenityOS developers.
+ * Copyright (c) 2021-2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibWeb/CSS/Parser/StyleBlockRule.h>
+
+namespace Web::CSS {
+
+StyleBlockRule::StyleBlockRule() = default;
+StyleBlockRule::StyleBlockRule(Token token, Vector<Parser::ComponentValue>&& values)
+    : m_token(move(token))
+    , m_values(move(values))
+{
+}
+StyleBlockRule::~StyleBlockRule() = default;
+
+String StyleBlockRule::to_string() const
+{
+    StringBuilder builder;
+
+    builder.append(m_token.bracket_string());
+    builder.join(" ", m_values);
+    builder.append(m_token.bracket_mirror_string());
+
+    return builder.to_string();
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
index fc164cfaa7..34314fa376 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleBlockRule.h
@@ -20,11 +20,7 @@ class StyleBlockRule : public RefCounted<StyleBlockRule> {
 
 public:
     StyleBlockRule();
-    explicit StyleBlockRule(Token token, Vector<Parser::ComponentValue>&& values)
-        : m_token(move(token))
-        , m_values(move(values))
-    {
-    }
+    StyleBlockRule(Token, Vector<Parser::ComponentValue>&&);
     ~StyleBlockRule();
 
     bool is_curly() const { return m_token.is(Token::Type::OpenCurly); }
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp b/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
index b14f857312..989ad0f421 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/StyleRules.cpp
@@ -33,9 +33,6 @@ StyleRule::StyleRule(StyleRule::Type type)
 }
 StyleRule::~StyleRule() = default;
 
-StyleBlockRule::StyleBlockRule() = default;
-StyleBlockRule::~StyleBlockRule() = default;
-
 Declaration::Declaration() = default;
 Declaration::~Declaration() = default;
 
@@ -87,17 +84,6 @@ String StyleRule::to_string() const
     return builder.to_string();
 }
 
-String StyleBlockRule::to_string() const
-{
-    StringBuilder builder;
-
-    builder.append(m_token.bracket_string());
-    append_with_to_string(builder, " ", m_values);
-    builder.append(m_token.bracket_mirror_string());
-
-    return builder.to_string();
-}
-
 String Declaration::to_string() const
 {
     StringBuilder builder;