diff --git a/clang.spec b/clang.spec
index 954cd8d9bf5d3cf58d2a969b8b522ba4613315dd..9a8a7b480e7cd990dcac7e3d064b5d0dc4d0394d 100644
--- a/clang.spec
+++ b/clang.spec
@@ -6,7 +6,7 @@
 
 Name:		clang
 Version:	10.0.1
-Release:	3
+Release:	4
 License:	GPL-2.0-only and Apache-2.0 and MIT
 Summary:	An "LLVM native" C/C++/Objective-C compiler
 URL:		http://llvm.org
@@ -107,8 +107,8 @@ cd _build
 %cmake .. \
 	-DLLVM_LINK_LLVM_DYLIB:BOOL=ON \
 	-DCMAKE_BUILD_TYPE=RelWithDebInfo \
-	-DCMAKE_C_FLAGS_RELWITHDEBINFO="%{optflags}" \
-	-DCMAKE_CXX_FLAGS_RELWITHDEBINFO="%{optflags}" \
+	-DCMAKE_C_FLAGS_RELWITHDEBINFO="%{optflags} -DNDEBUG" \
+	-DCMAKE_CXX_FLAGS_RELWITHDEBINFO="%{optflags} -DNDEBUG" \
 	-DLLVM_CONFIG:FILEPATH=/usr/bin/llvm-config-%{__isa_bits} \
 	-DCLANG_INCLUDE_TESTS:BOOL=ON \
 	-DLLVM_EXTERNAL_LIT=%{_bindir}/lit \
@@ -240,6 +240,9 @@ ln -s clang++ %{buildroot}%{_bindir}/clang++-%{maj_ver}
 %{_bindir}/git-clang-format
 
 %changelog
+* Fri Apr 30 2021 licihua <licihua@huawei.com> - 10.0.1-4
+- Reduce build time.
+
 * Thu Apr 29 2021 licihua <licihua@huawei.com> - 10.0.1-3
 - Reduce debuginfo verbosity.