diff --git a/lisp/progmodes/c-ts-mode.el b/lisp/progmodes/c-ts-mode.el
index 3afd7a4a913..eb07eb74676 100644
--- a/lisp/progmodes/c-ts-mode.el
+++ b/lisp/progmodes/c-ts-mode.el
@@ -282,12 +282,19 @@ PARENT and BOL are like other anchor functions."
               (or (treesit-node-prev-sibling node t)
                   (treesit-node-prev-sibling
                    (treesit-node-first-child-for-pos parent bol) t)
-                  (treesit-node-child parent -1 t))))
-    (while (and prev-sibling
-                (equal "labeled_statement"
-                       (treesit-node-type prev-sibling)))
-      ;; The 0th child is the label, the 1th the colon.
-      (setq prev-sibling (treesit-node-child prev-sibling 2)))
+                  (treesit-node-child parent -1 t)))
+             (continue t))
+    (while (and prev-sibling continue)
+      (pcase (treesit-node-type prev-sibling)
+        ;; Get the statement in the label.
+        ("labeled_statement"
+         (setq prev-sibling (treesit-node-child prev-sibling 2)))
+        ;; Get the last statement in the preproc.  Tested by
+        ;; "Prev-Sibling When Prev-Sibling is Preproc" test.
+        ((or "preproc_if" "preproc_ifdef" "preproc_elif" "preproc_else")
+         (setq prev-sibling (treesit-node-child prev-sibling -2)))
+        ;; Don't do anything special.
+        (_ (setq continue nil))))
     ;; This could be nil if a) there is no prev-sibling or b)
     ;; prev-sibling doesn't have a child.
     (treesit-node-start prev-sibling)))