diff --git a/mfbt/Attributes.h b/mfbt/Attributes.h
index ff5b7f74951b..4c4b1d2baeb8 100644
--- a/mfbt/Attributes.h
+++ b/mfbt/Attributes.h
@@ -486,6 +486,24 @@
 #  define MOZ_LIFETIME_CAPTURE_BY(x) /* nothing */
 #endif
 
+/**
+ * MOZ_LIFETIME_CAPTURE_BY_THIS is the equivalent of
+ * MOZ_LIFETIME_CAPTURE_BY(this). It needs to be spelled differently because
+ * clang 23 deprecated passing `this` to lifetime_capture_by in favor of the
+ * dedicated lifetime_capture_by_this attribute.
+ */
+#if defined(__clang__) && defined(__has_cpp_attribute)
+#  if __has_cpp_attribute(clang::lifetime_capture_by_this)
+#    define MOZ_LIFETIME_CAPTURE_BY_THIS [[clang::lifetime_capture_by_this]]
+#  elif __has_cpp_attribute(clang::lifetime_capture_by)
+#    define MOZ_LIFETIME_CAPTURE_BY_THIS [[clang::lifetime_capture_by(this)]]
+#  else
+#    define MOZ_LIFETIME_CAPTURE_BY_THIS /* nothing */
+#  endif
+#else
+#  define MOZ_LIFETIME_CAPTURE_BY_THIS /* nothing */
+#endif
+
 /**
  * MOZ_REINITIALIZES tells static analyser that a call to the associated
  * method leave it in an initialized state, typically after a std::move.
diff --git a/mfbt/api.yml b/mfbt/api.yml
index ae4268a04f2c..0cf113412257 100644
--- a/mfbt/api.yml
+++ b/mfbt/api.yml
@@ -101,6 +101,7 @@ Attributes.h:
     - MOZ_GSL_POINTER
     - MOZ_LIFETIME_BOUND
     - MOZ_LIFETIME_CAPTURE_BY
+    - MOZ_LIFETIME_CAPTURE_BY_THIS
     - MOZ_STANDALONE_DEBUG
     - MOZ_NULL_AFTER_MOVE
     - MOZ_PUSH_DISABLE_NONTRIVIAL_UNION_WARNINGS
diff --git a/xpcom/string/nsTDependentString.h b/xpcom/string/nsTDependentString.h
index a4e99bd4f6cb..d0191c4efc2f 100644
--- a/xpcom/string/nsTDependentString.h
+++ b/xpcom/string/nsTDependentString.h
@@ -103,12 +103,12 @@ class MOZ_GSL_POINTER nsTDependentString : public nsTString<T> {
    */
 
   using nsTString<T>::Rebind;
-  void Rebind(const char_type* aData MOZ_LIFETIME_CAPTURE_BY(this)) {
+  void Rebind(const char_type* aData MOZ_LIFETIME_CAPTURE_BY_THIS) {
     Rebind(aData, char_traits::length(aData));
   }
 
-  void Rebind(const char_type* aStart MOZ_LIFETIME_CAPTURE_BY(this),
-              const char_type* aEnd MOZ_LIFETIME_CAPTURE_BY(this));
+  void Rebind(const char_type* aStart MOZ_LIFETIME_CAPTURE_BY_THIS,
+              const char_type* aEnd MOZ_LIFETIME_CAPTURE_BY_THIS);
   void Rebind(const string_type&, index_type aStartPos);
 
  protected: