diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c6f32b0804..004f4a622e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ jobs:
     env:
       CC: ${{ matrix.compiler }}
       GCC_VER: 14
-      CLANG_VER: 20
+      CLANG_VER: 21
       TEST: test
       SRCDIR: ./src
       LEAK_CFLAGS: -DEXITFREE
diff --git a/src/if_ruby.c b/src/if_ruby.c
index 2a00a99b0b..6e7805d5bb 100644
--- a/src/if_ruby.c
+++ b/src/if_ruby.c
@@ -107,15 +107,21 @@
 # undef SIZEOF_TIME_T
 #endif
 
-#ifdef __GNUC__
+#if defined(__GNUC__) || defined(__clang__)
 # pragma GCC diagnostic push
 # pragma GCC diagnostic ignored "-Wunused-parameter"
 #endif
+
+#if defined(__clang__) && (__clang_major__ >= 21)
+# pragma GCC diagnostic ignored "-Wdefault-const-init-field-unsafe"
+#endif
+
 #include <ruby.h>
-#ifdef __GNUC__
+#include <ruby/encoding.h>
+
+#if defined(__GNUC__) || defined(__clang__)
 # pragma GCC diagnostic pop
 #endif
-#include <ruby/encoding.h>
 
 // See above.
 #ifdef SIZEOF_TIME_T
diff --git a/src/version.c b/src/version.c
index c26e95b923..18623c88ea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -724,6 +724,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1729,
 /**/
     1728,
 /**/