diff --git a/clang/lib/Driver/ToolChains/Clang.cpp b/clang/lib/Driver/ToolChains/Clang.cpp
--- a/clang/lib/Driver/ToolChains/Clang.cpp
+++ b/clang/lib/Driver/ToolChains/Clang.cpp
@@ -4041,9 +4041,10 @@
   if (Triple.isOSWindows() && (Triple.getArch() == llvm::Triple::arm ||
                                Triple.getArch() == llvm::Triple::thumb)) {
     unsigned Offset = Triple.getArch() == llvm::Triple::arm ? 4 : 6;
-    unsigned Version;
-    Triple.getArchName().substr(Offset).getAsInteger(10, Version);
-    if (Version < 7)
+    unsigned Version = 0;
+    bool Failure =
+        Triple.getArchName().substr(Offset).consumeInteger(10, Version);
+    if (Failure || Version < 7)
       D.Diag(diag::err_target_unsupported_arch) << Triple.getArchName()
                                                 << TripleStr;
   }
diff --git a/clang/test/Driver/windows-thumbv7em.cpp b/clang/test/Driver/windows-thumbv7em.cpp
new file mode 100644
--- /dev/null
+++ b/clang/test/Driver/windows-thumbv7em.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang -target thumb-none-windows-eabi-coff -mcpu=cortex-m7 -### -c %s 2>&1 \
+// RUN: | FileCheck %s --check-prefix CHECK-V7
+// CHECK-V7-NOT: error: the target architecture 'thumbv7em' is not supported by the target 'thumbv7em-none-windows-eabi'
+
+// RUN: %clang -target thumb-none-windows-eabi-coff -mcpu=cortex-m1 -### -c %s 2>&1 \
+// RUN: | FileCheck %s --check-prefix CHECK-V6
+// CHECK-V6: error: the target architecture 'thumbv6m' is not supported by the target 'thumbv6m-none-windows-eabi'
+