diff --git a/llvm/lib/Support/TargetParser.cpp b/llvm/lib/Support/TargetParser.cpp
index ea12d8001a39..b96ca084e9bf 100644
--- a/llvm/lib/Support/TargetParser.cpp
+++ b/llvm/lib/Support/TargetParser.cpp
@@ -537,7 +537,7 @@ StringRef llvm::AArch64::getDefaultCPU(StringRef Arch) {
 }
 
 unsigned llvm::AArch64::checkArchVersion(StringRef Arch) {
-  if (Arch[0] == 'v' && std::isdigit(Arch[1]))
+  if (Arch.size() >= 2 && Arch[0] == 'v' && std::isdigit(Arch[1]))
     return (Arch[1] - 48);
   return 0;
 }
@@ -633,7 +633,7 @@ StringRef llvm::ARM::getCanonicalArchName(StringRef Arch) {
   // Only match non-marketing names
   if (offset != StringRef::npos) {
     // Must start with 'vN'.
-    if (A[0] != 'v' || !std::isdigit(A[1]))
+    if (A.size() >= 2 && (A[0] != 'v' || !std::isdigit(A[1])))
       return Error;
     // Can't have an extra 'eb'.
     if (A.find("eb") != StringRef::npos)
diff --git a/llvm/unittests/Support/TargetParserTest.cpp b/llvm/unittests/Support/TargetParserTest.cpp
index dcef40345f05..48fffca1aa18 100644
--- a/llvm/unittests/Support/TargetParserTest.cpp
+++ b/llvm/unittests/Support/TargetParserTest.cpp
@@ -278,6 +278,12 @@ TEST(TargetParserTest, testARMCPU) {
                          "7-S"));
 }
 
+TEST(TargetParserTest, testInvalidARMArch) {
+  auto InvalidArchStrings = {"armv", "armv99", "noarm"};
+  for (const char* InvalidArch : InvalidArchStrings)
+    EXPECT_EQ(ARM::parseArch(InvalidArch), ARM::ArchKind::INVALID);
+}
+
 bool testARMArch(StringRef Arch, StringRef DefaultCPU, StringRef SubArch,
                  unsigned ArchAttr) {
   ARM::ArchKind AK = ARM::parseArch(Arch);