diff --git a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
index 95216368492ca..d72d021f44838 100644
--- a/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
+++ b/clang-tools-extra/clang-tidy/ExpandModularHeadersPPCallbacks.h
@@ -137,7 +137,7 @@ class ExpandModularHeadersPPCallbacks : public PPCallbacks {
   std::unique_ptr<Preprocessor> PP;
   bool EnteredMainFile = false;
   bool StartedLexing = false;
-  Token CurrentToken;
+  Token CurrentToken = Token();
 };
 
 } // namespace tooling
diff --git a/clang-tools-extra/clang-tidy/bugprone/FloatLoopCounterCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/FloatLoopCounterCheck.cpp
index adf2d2b4bcc07..38a0234337756 100644
--- a/clang-tools-extra/clang-tidy/bugprone/FloatLoopCounterCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/FloatLoopCounterCheck.cpp
@@ -31,6 +31,7 @@ void FloatLoopCounterCheck::registerMatchers(MatchFinder *Finder) {
 
 void FloatLoopCounterCheck::check(const MatchFinder::MatchResult &Result) {
   const auto *FS = Result.Nodes.getNodeAs<ForStmt>("for");
+  assert(FS && "FS should not be null");
 
   diag(FS->getInc()->getBeginLoc(), "loop induction expression should not have "
                                     "floating-point type")
diff --git a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsAvoidUncheckedContainerAccessCheck.cpp b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsAvoidUncheckedContainerAccessCheck.cpp
index 83803a3e81937..67ce8e5cf176c 100644
--- a/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsAvoidUncheckedContainerAccessCheck.cpp
+++ b/clang-tools-extra/clang-tidy/cppcoreguidelines/ProBoundsAvoidUncheckedContainerAccessCheck.cpp
@@ -177,7 +177,7 @@ void ProBoundsAvoidUncheckedContainerAccessCheck::check(
     }
   } else if (const auto *MCE = dyn_cast<CXXMemberCallExpr>(MatchedExpr)) {
     // Case: a.operator[](i) or a->operator[](i)
-    const auto *Callee = dyn_cast<MemberExpr>(MCE->getCallee());
+    const auto *Callee = cast<MemberExpr>(MCE->getCallee());
 
     if (FixMode == At) {
       // Cases: a.operator[](i) => a.at(i) and a->operator[](i) => a->at(i)