diff --git a/infra/base-images/base-clang/Dockerfile b/infra/base-images/base-clang/Dockerfile
index 1c5bd02686bd..f24b5703d394 100644
--- a/infra/base-images/base-clang/Dockerfile
+++ b/infra/base-images/base-clang/Dockerfile
@@ -56,6 +56,6 @@ ENV CCC "clang++"
 # FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION is described at
 # https://llvm.org/docs/LibFuzzer.html#fuzzer-friendly-build-mode
 
-ENV CFLAGS "-O1 -fno-omit-frame-pointer -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION"
+ENV CFLAGS "-O1 -fno-omit-frame-pointer -D_LIBCPP_DEBUG=1 -gline-tables-only -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION"
 ENV CXXFLAGS_EXTRA "-stdlib=libc++"
 ENV CXXFLAGS "$CFLAGS $CXXFLAGS_EXTRA"
diff --git a/infra/base-images/base-clang/checkout_build_install_llvm.sh b/infra/base-images/base-clang/checkout_build_install_llvm.sh
index 65f0ea554e3e..3f3f982c282c 100755
--- a/infra/base-images/base-clang/checkout_build_install_llvm.sh
+++ b/infra/base-images/base-clang/checkout_build_install_llvm.sh
@@ -98,6 +98,7 @@ function cmake_llvm {
       -DLIBCXX_ENABLE_SHARED=OFF \
       -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
       -DLIBCXXABI_ENABLE_SHARED=OFF \
+      -DLIBCXX_ENABLE_DEBUG_MODE=ON \
       -DCMAKE_BUILD_TYPE=Release \
       -DLLVM_TARGETS_TO_BUILD="$TARGET_TO_BUILD" \
       -DLLVM_ENABLE_PROJECTS="$PROJECTS_TO_BUILD" \
@@ -220,6 +221,7 @@ function cmake_libcxx {
       -DLIBCXX_ENABLE_SHARED=OFF \
       -DLIBCXX_ENABLE_STATIC_ABI_LIBRARY=ON \
       -DLIBCXXABI_ENABLE_SHARED=OFF \
+      -DLIBCXX_ENABLE_DEBUG_MODE=ON \
       -DCMAKE_BUILD_TYPE=Release \
       -DLLVM_TARGETS_TO_BUILD="$TARGET_TO_BUILD" \
       -DLLVM_ENABLE_PROJECTS="libcxx;libcxxabi" \