diff --git a/clang-tools-extra/clangd/index/MemIndex.h b/clang-tools-extra/clangd/index/MemIndex.h
index fba2c1a7120a2..ff427f65fdf06 100644
--- a/clang-tools-extra/clangd/index/MemIndex.h
+++ b/clang-tools-extra/clangd/index/MemIndex.h
@@ -93,7 +93,7 @@ class MemIndex : public SymbolIndex {
   // Set of files which were used during this index build.
   llvm::StringSet<> Files;
   // Contents of the index (symbols, references, etc.)
-  IndexContents IdxContents;
+  IndexContents IdxContents = IndexContents::None;
   std::shared_ptr<void> KeepAlive; // poor man's move-only std::any
   // Size of memory retained by KeepAlive.
   size_t BackingDataSize = 0;
diff --git a/clang-tools-extra/clangd/index/dex/Dex.h b/clang-tools-extra/clangd/index/dex/Dex.h
index 69e161d51135b..84397458107de 100644
--- a/clang-tools-extra/clangd/index/dex/Dex.h
+++ b/clang-tools-extra/clangd/index/dex/Dex.h
@@ -123,7 +123,7 @@ class Dex : public SymbolIndex {
   // Set of files which were used during this index build.
   llvm::StringSet<> Files;
   // Contents of the index (symbols, references, etc.)
-  IndexContents IdxContents;
+  IndexContents IdxContents = IndexContents::None;
   // Size of memory retained by KeepAlive.
   size_t BackingDataSize = 0;
 };