diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index 4137b593c2..a377b06e47 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -1485,6 +1485,27 @@ Element::GetElementsByClassName(const nsAString& aClassNames,
   return NS_OK;
 }
 
+CSSPseudoElementType
+Element::GetPseudoElementType() const {
+  if (!HasProperties()) {
+    return CSSPseudoElementType::NotPseudo;
+  }
+  nsresult rv = NS_OK;
+  auto raw = GetProperty(nsGkAtoms::pseudoProperty, &rv);
+  if (rv == NS_PROPTABLE_PROP_NOT_THERE) {
+    return CSSPseudoElementType::NotPseudo;
+  }
+  return CSSPseudoElementType(reinterpret_cast<uintptr_t>(raw));
+}
+
+void
+Element::SetPseudoElementType(CSSPseudoElementType aPseudo) {
+  static_assert(sizeof(CSSPseudoElementType) <= sizeof(uintptr_t),
+                "Need to be able to store this in a void*");
+  MOZ_ASSERT(aPseudo != CSSPseudoElementType::NotPseudo);
+  SetProperty(nsGkAtoms::pseudoProperty, reinterpret_cast<void*>(aPseudo));
+}
+
 /**
  * Returns the count of descendants (inclusive of aContent) in
  * the uncomposed document that are explicitly set as editable.
diff --git a/dom/base/Element.h b/dom/base/Element.h
index c602fce1fe..cf342e94d1 100644
--- a/dom/base/Element.h
+++ b/dom/base/Element.h
@@ -814,24 +814,9 @@ public:
   already_AddRefed<nsIHTMLCollection>
     GetElementsByClassName(const nsAString& aClassNames);
 
-  CSSPseudoElementType GetPseudoElementType() const {
-    if (!HasProperties()) {
-      return CSSPseudoElementType::NotPseudo;
-    }
-    nsresult rv = NS_OK;
-    auto raw = GetProperty(nsGkAtoms::pseudoProperty, &rv);
-    if (rv == NS_PROPTABLE_PROP_NOT_THERE) {
-      return CSSPseudoElementType::NotPseudo;
-    }
-    return CSSPseudoElementType(reinterpret_cast<uintptr_t>(raw));
-  }
+  CSSPseudoElementType GetPseudoElementType() const;
 
-  void SetPseudoElementType(CSSPseudoElementType aPseudo) {
-    static_assert(sizeof(CSSPseudoElementType) <= sizeof(uintptr_t),
-                  "Need to be able to store this in a void*");
-    MOZ_ASSERT(aPseudo != CSSPseudoElementType::NotPseudo);
-    SetProperty(nsGkAtoms::pseudoProperty, reinterpret_cast<void*>(aPseudo));
-  }
+  void SetPseudoElementType(CSSPseudoElementType aPseudo);
 
 private:
   /**