diff --git a/yjit/bindgen/src/main.rs b/yjit/bindgen/src/main.rs
index 5abd445dae76f2..5d30d7b288b37d 100644
--- a/yjit/bindgen/src/main.rs
+++ b/yjit/bindgen/src/main.rs
@@ -64,7 +64,7 @@ fn main() {
 
         // From include/ruby/internal/intern/string.h
         .allowlist_function("rb_utf8_str_new")
-        .allowlist_function("rb_str_append")
+        .allowlist_function("rb_str_buf_append")
         .allowlist_function("rb_str_dup")
 
         // This struct is public to Ruby C extensions
diff --git a/yjit/src/codegen.rs b/yjit/src/codegen.rs
index 12c97411b0f59e..84f4ff4897b890 100644
--- a/yjit/src/codegen.rs
+++ b/yjit/src/codegen.rs
@@ -3792,7 +3792,7 @@ fn jit_rb_str_concat(
 
     // If encodings are different, use a slower encoding-aware concatenate
     cb.write_label(enc_mismatch);
-    call_ptr(cb, REG0, rb_str_append as *const u8);
+    call_ptr(cb, REG0, rb_str_buf_append as *const u8);
     // Drop through to return
 
     cb.write_label(ret_label);
diff --git a/yjit/src/cruby_bindings.inc.rs b/yjit/src/cruby_bindings.inc.rs
index 44f87a8482cf08..88ad8e563c472a 100644
--- a/yjit/src/cruby_bindings.inc.rs
+++ b/yjit/src/cruby_bindings.inc.rs
@@ -224,10 +224,10 @@ extern "C" {
     ) -> VALUE;
 }
 extern "C" {
-    pub fn rb_str_dup(str_: VALUE) -> VALUE;
+    pub fn rb_str_buf_append(dst: VALUE, src: VALUE) -> VALUE;
 }
 extern "C" {
-    pub fn rb_str_append(dst: VALUE, src: VALUE) -> VALUE;
+    pub fn rb_str_dup(str_: VALUE) -> VALUE;
 }
 extern "C" {
     pub fn rb_str_intern(str_: VALUE) -> VALUE;