diff --git a/lisp/progmodes/c-ts-mode.el b/lisp/progmodes/c-ts-mode.el
index f58fac40ce2..66f179f2f7f 100644
--- a/lisp/progmodes/c-ts-mode.el
+++ b/lisp/progmodes/c-ts-mode.el
@@ -138,6 +138,7 @@ MODE is either `c' or `cpp'."
            ((parent-is "function_definition") parent-bol 0)
            ((parent-is "conditional_expression") first-sibling 0)
            ((parent-is "assignment_expression") parent-bol c-ts-mode-indent-offset)
+           ((parent-is "concatenated_string") parent-bol c-ts-mode-indent-offset)
            ((parent-is "comma_expression") first-sibling 0)
            ((parent-is "init_declarator") parent-bol c-ts-mode-indent-offset)
            ((parent-is "parenthesized_expression") first-sibling 1)