diff --git a/clang-tools-extra/clang-tidy/bugprone/BadSignalToKillThreadCheck.cpp b/clang-tools-extra/clang-tidy/bugprone/BadSignalToKillThreadCheck.cpp
--- a/clang-tools-extra/clang-tidy/bugprone/BadSignalToKillThreadCheck.cpp
+++ b/clang-tools-extra/clang-tidy/bugprone/BadSignalToKillThreadCheck.cpp
@@ -30,7 +30,8 @@
 
 void BadSignalToKillThreadCheck::check(const MatchFinder::MatchResult &Result) {
   const auto IsSigterm = [](const auto &KeyValue) -> bool {
-    return KeyValue.first->getName() == "SIGTERM";
+    return KeyValue.first->getName() == "SIGTERM" &&
+           KeyValue.first->hasMacroDefinition();
   };
   const auto TryExpandAsInteger =
       [](Preprocessor::macro_iterator It) -> Optional<unsigned> {
@@ -38,6 +39,8 @@
       return llvm::None;
     const MacroInfo *MI = PP->getMacroInfo(It->first);
     const Token &T = MI->tokens().back();
+    if (!T.isLiteral() || !T.getLiteralData())
+      return llvm::None;
     StringRef ValueStr = StringRef(T.getLiteralData(), T.getLength());
 
     llvm::APInt IntValue;
diff --git a/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp b/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
--- a/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
+++ b/clang-tools-extra/clangd/unittests/DiagnosticsTests.cpp
@@ -438,6 +438,21 @@
   EXPECT_THAT(TU.build().getDiagnostics(), UnorderedElementsAre());
 }
 
+TEST(DiagnosticTest, ClangTidyBadSignalToKillThread) {
+  Annotations Main(R"cpp(
+    #define SIGTERM 15
+    using pthread_t = int;
+    int pthread_kill(pthread_t thread, int sig);
+    int func() {
+      pthread_t thread;
+      return pthread_kill(thread, 0);
+    }
+  )cpp");
+  TestTU TU = TestTU::withCode(Main.code());
+  TU.ClangTidyChecks = "-*,bugprone-bad-signal-to-kill-thread";
+  EXPECT_THAT(TU.build().getDiagnostics(), UnorderedElementsAre()); // no-crash
+}
+
 TEST(DiagnosticsTest, Preprocessor) {
   // This looks like a preamble, but there's an #else in the middle!
   // Check that:
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-sigterm-not-a-literal.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-sigterm-not-a-literal.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-sigterm-not-a-literal.cpp
@@ -0,0 +1,10 @@
+// RUN: clang-tidy %s --checks="-*,bugprone-bad-signal-to-kill-thread"
+
+#define SIGTERM ((unsigned)15) // no-crash
+using pthread_t = int;
+int pthread_kill(pthread_t thread, int sig);
+
+int func() {
+  pthread_t thread;
+  return pthread_kill(thread, 0);
+}
diff --git a/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-undef-sigterm.cpp b/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-undef-sigterm.cpp
new file mode 100644
--- /dev/null
+++ b/clang-tools-extra/test/clang-tidy/checkers/bugprone-bad-signal-to-kill-thread-undef-sigterm.cpp
@@ -0,0 +1,11 @@
+// RUN: clang-tidy %s --checks="-*,bugprone-bad-signal-to-kill-thread"
+
+#define SIGTERM 15
+#undef SIGTERM // no-crash
+using pthread_t = int;
+int pthread_kill(pthread_t thread, int sig);
+
+int func() {
+  pthread_t thread;
+  return pthread_kill(thread, 0);
+}