diff --git a/cmake-flags-concat.patch b/cmake-flags-concat.patch
new file mode 100644
index 0000000..cbf735e
--- /dev/null
+++ b/cmake-flags-concat.patch
@@ -0,0 +1,15 @@
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index 9773b2c..e1879a9 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -136,8 +136,8 @@ set( LLVM_VERSION_DEFINE "-DHAVE_LLVM=0x${LLVM_MAJOR}0${LLVM_MINOR}" )
+ 
+ # LLVM 13 enables standard includes by default
+ if( ${LLVM_VERSION} VERSION_GREATER "12.99.99" )
+-				set( CMAKE_LLAsm_FLAGS ${CMAKE_LLAsm_FLAGS} -cl-no-stdinc )
+-				set( CMAKE_CLC_FLAGS ${CMAKE_CLC_FLAGS} -cl-no-stdinc )
++				set( CMAKE_LLAsm_FLAGS "${CMAKE_LLAsm_FLAGS} -cl-no-stdinc" )
++				set( CMAKE_CLC_FLAGS "${CMAKE_CLC_FLAGS} -cl-no-stdinc" )
+ endif()
+ 
+ enable_language( CLC LLAsm )
diff --git a/libclc-14.0.0.src.tar.xz b/libclc-14.0.0.src.tar.xz
deleted file mode 100644
index 933dacd..0000000
--- a/libclc-14.0.0.src.tar.xz
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:39fe8fbc112d335b483023c7e9dec2eac7e0be7062c5b088774de935d7c7cdb8
-size 130444
diff --git a/libclc-15.0.0.src.tar.xz b/libclc-15.0.0.src.tar.xz
new file mode 100644
index 0000000..a563a71
--- /dev/null
+++ b/libclc-15.0.0.src.tar.xz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:77034efe5f5daddc8a8ce7607b8e74e10a9ab9c9929caea62e29b81bbdad2f15
+size 125712
diff --git a/libclc.changes b/libclc.changes
index eac800e..69fecce 100644
--- a/libclc.changes
+++ b/libclc.changes
@@ -1,3 +1,12 @@
+-------------------------------------------------------------------
+Thu Sep 29 21:33:37 UTC 2022 - Aaron Puchert <aaronpuchert@alice-dsl.net>
+
+- Update to version 0.2.0+llvm15.0.0.
+- Compile without opaque pointers for now because Mesa doesn't
+  support them yet.
+- Add cmake-flags-concat.patch to ensure proper concatenation of
+  build flags: CMAKE_<LANG>_FLAGS is a string and not a list.
+
 -------------------------------------------------------------------
 Thu Aug 25 13:33:10 UTC 2022 - Stefan Dirsch <sndirsch@suse.com>
 
@@ -6,7 +15,7 @@ Thu Aug 25 13:33:10 UTC 2022 - Stefan Dirsch <sndirsch@suse.com>
 -------------------------------------------------------------------
 Fri Apr  1 21:44:03 UTC 2022 - Aaron Puchert <aaronpuchert@alice-dsl.net>
 
-- Update to version 0.2.0+14.0.0.
+- Update to version 0.2.0+llvm14.0.0.
 
 -------------------------------------------------------------------
 Mon Nov 15 09:30:31 UTC 2021 - Stefan Dirsch <sndirsch@suse.com>
diff --git a/libclc.spec b/libclc.spec
index 41c1c6c..3bece5b 100644
--- a/libclc.spec
+++ b/libclc.spec
@@ -16,7 +16,7 @@
 #
 
 
-%define _libclc_llvm_ver 14.0.0
+%define _libclc_llvm_ver 15.0.0
 %define _version %_libclc_llvm_ver%{?_rc:rc%_rc}
 %define _tagver %_libclc_llvm_ver%{?_rc:-rc%_rc}
 
@@ -29,6 +29,8 @@ Group:          Development/Libraries/C and C++
 URL:            https://libclc.llvm.org/
 Source0:        https://github.com/llvm/llvm-project/releases/download/llvmorg-%{_tagver}/%{name}-%{_version}.src.tar.xz
 Source1:        %{name}-rpmlintrc
+# PATCH-FIX-UPSTREAM: CMAKE_<LANG>_FLAGS is a string and not a list.
+Patch0:         cmake-flags-concat.patch
 BuildRequires:  cmake
 %if 0%{?suse_version} >= 1550
 BuildRequires:  clang-devel
@@ -56,15 +58,19 @@ Library requirements of the OpenCL C programming language.
 
 %prep
 %setup -q -n libclc-%{_version}.src
+%patch0 -p1
 
 %build
 # The libraries are bitcode files, so LTO is neither supported nor does it help.
 %define _lto_cflags %{nil}
 
+# For now we turn off opaque pointers - Clang uses them by default, but Mesa doesn't support them yet.
 # TODO: For building all targets, we need llvm-spirv.
 %cmake \
   -DCMAKE_C_COMPILER=clang \
   -DCMAKE_CXX_COMPILER=clang++ \
+  -DCMAKE_CLC_FLAGS="-Xclang -no-opaque-pointers" \
+  -DCMAKE_LLAsm_FLAGS="-Xclang -no-opaque-pointers" \
   -DENABLE_RUNTIME_SUBNORMAL:BOOL=ON \
   -DLIBCLC_TARGETS_TO_BUILD="amdgcn--;amdgcn--amdhsa;amdgcn-mesa-mesa3d;r600--;nvptx--;nvptx64--;nvptx--nvidiacl;nvptx64--nvidiacl"
 %cmake_build