diff --git a/clang-tools-extra/clangd/tool/ClangdMain.cpp b/clang-tools-extra/clangd/tool/ClangdMain.cpp
--- a/clang-tools-extra/clangd/tool/ClangdMain.cpp
+++ b/clang-tools-extra/clangd/tool/ClangdMain.cpp
@@ -185,7 +185,7 @@
     Hidden,
 };
 
-opt<bool> DecisionForestBase{
+opt<float> DecisionForestBase{
     "decision-forest-base",
     cat(Features),
     desc("Base for exponentiating the prediction from DecisionForest."),