diff --git a/fix-build-with-clang-19.patch b/fix-build-with-clang-19.patch
new file mode 100644
index 0000000000000000000000000000000000000000..488b4aa69b24f3bdbe6e5170c4117f9a2b5c6286
--- /dev/null
+++ b/fix-build-with-clang-19.patch
@@ -0,0 +1,42 @@
+From eb919d3ebee4d8c9f382fd62305e6af5725c3a23 Mon Sep 17 00:00:00 2001
+From: jchzhou <zhoujiacheng@iscas.ac.cn>
+Date: Wed, 16 Apr 2025 22:59:27 +0800
+Subject: [PATCH] fix build with clang 19
+
+Clang 19 is now more strict about undefined integral expressions used as
+constants in enum, which results in errors compiling java/openjdk11,
+similar to:
+
+    /wrkdirs/usr/ports/java/openjdk11/work/jdk11u-jdk-11.0.24-8-1/src/jdk.pack/share/native/common-unpack/constants.h:206:33: error: expression is not an integral constant expression
+      206 |     AO_UNUSED_MBZ             = (-1)<<13, // options bits reserved for future use.
+          |                                 ^~~~~~~~
+    /wrkdirs/usr/ports/java/openjdk11/work/jdk11u-jdk-11.0.24-8-1/src/jdk.pack/share/native/common-unpack/constants.h:206:37: note: left shift of negative value -1
+      206 |     AO_UNUSED_MBZ             = (-1)<<13, // options bits reserved for future use.
+          |                                     ^
+
+Replace the negative value with ~0u to fix this error.
+
+Source: https://cgit.freebsd.org/ports/patch/?id=d2ae63c6feffda05eb643520dd851451ee337f53
+Signed-off-by: Dimitry Andric <dim@FreeBSD.org>
+
+Tested-by: jchzhou <zhoujiacheng@iscas.ac.cn>o
+---
+ src/jdk.pack/share/native/common-unpack/constants.h | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/src/jdk.pack/share/native/common-unpack/constants.h b/src/jdk.pack/share/native/common-unpack/constants.h
+index 8d8376dd2..0bc0e00dc 100644
+--- a/src/jdk.pack/share/native/common-unpack/constants.h
++++ b/src/jdk.pack/share/native/common-unpack/constants.h
+@@ -203,7 +203,7 @@ enum {
+     AO_HAVE_FIELD_FLAGS_HI    = 1<<10,
+     AO_HAVE_METHOD_FLAGS_HI   = 1<<11,
+     AO_HAVE_CODE_FLAGS_HI     = 1<<12,
+-    AO_UNUSED_MBZ             = (-1)<<13, // options bits reserved for future use.
++    AO_UNUSED_MBZ             = (~0u)<<13, // options bits reserved for future use.
+ 
+ #define ARCHIVE_BIT_DO(F) \
+          F(AO_HAVE_SPECIAL_FORMATS) \
+-- 
+2.49.0
+
diff --git a/openjdk-11.spec b/openjdk-11.spec
index 2c687e27989867f5e949dfe9b99b5bf1c5137832..5e08a88c97377e5bf3af1691901004bf1cbf15e4 100644
--- a/openjdk-11.spec
+++ b/openjdk-11.spec
@@ -95,6 +95,9 @@
 # We replace it with -Wformat (required by -Werror=format-security) and -Wno-cpp to avoid FORTIFY_SOURCE warnings
 # We filter out -fexceptions as the HotSpot build explicitly does -fno-exceptions and it's otherwise the default for C++
 %global ourflags %(echo %optflags | sed -e 's|-Wall|-Wformat -Wno-cpp|' | sed -r -e 's|-O[0-9]*||')
+%if "%{?toolchain}" == "clang"
+%global ourflags "$ourflags -Wno-register"
+%endif
 %global ourcppflags %(echo %ourflags | sed -e 's|-fexceptions||')
 %global ourldflags %{__global_ldflags}
 
@@ -773,7 +776,7 @@ Provides: java-src%{?1} = %{epoch}:%{version}-%{release}
 
 Name:    java-%{javaver}-%{origin}
 Version: %{newjavaver}.%{buildver}
-Release: 3
+Release: 4
 # java-1.5.0-ibm from jpackage.org set Epoch to 1 for unknown reasons
 # and this change was brought into RHEL-4. java-1.5.0-ibm packages
 # also included the epoch in their virtual provides. This created a
@@ -912,6 +915,9 @@ Patch94: change-ActivePrcoessorCount-only-for-HBase.patch
 Patch95: 8347965-tz-Update-Timezone-Data-to-2025a.patch
 Patch96: add-jbolt-feature.patch
 
+# fix building issues with clang
+Patch97: fix-build-with-clang-19.patch
+
 ############################################
 #
 # riscv64 specific patches
@@ -1222,6 +1228,7 @@ pushd %{top_level_dir_name}
 %ifarch sw_64
 %patch6000 -p1
 %endif
+%patch97 -p1
 popd # openjdk
 
 # Extract systemtap tapsets
@@ -1351,6 +1358,9 @@ bash ../configure \
     --with-num-cores="$NUM_PROC" \
     --disable-javac-server \
     --disable-warnings-as-errors \
+%if "%{?toolchain}" == "clang"
+    --with-toolchain-type=clang \
+%endif
 
 # Debug builds don't need same targets as release for
 # build speed-up
@@ -1751,6 +1761,9 @@ cjc.mainProgram(args) -- the returns from copy_jdk_configs.lua should not affect
 
 
 %changelog
+* Wed Apr 16 2025 jchzhou <zhoujiacheng@iscas.ac.cn> - 1:11.0.26.4-4
+- fix building issues with clang
+
 * Tue Apr 1 2025 2025 swcompiler <lc@wxiat.cn> - 1:11.0.26.4-3
 - add sw64 port to 11.0.26