Index: test/tools/llvm-size/unknown-radix.test
===================================================================
--- /dev/null
+++ test/tools/llvm-size/unknown-radix.test
@@ -0,0 +1,5 @@
+RUN: not llvm-size -radix=foo 2>&1 | FileCheck --check-prefix=CHECK-NOT-NUMERIC %s
+CHECK-NOT-NUMERIC: {{.*}}llvm-size{{(\.EXE|\.exe)?}}: for the -radix option: Cannot find option named 'foo'!
+
+RUN: not llvm-size -radix=4 2>&1 | FileCheck --check-prefix=CHECK-NUMERIC %s
+CHECK-NUMERIC: {{.*}}llvm-size{{(\.EXE|\.exe)?}}: for the -radix option: Cannot find option named '4'!
Index: tools/llvm-size/llvm-size.cpp
===================================================================
--- tools/llvm-size/llvm-size.cpp
+++ tools/llvm-size/llvm-size.cpp
@@ -71,9 +71,11 @@
 static bool ArchAll = false;
 
 enum RadixTy { octal = 8, decimal = 10, hexadecimal = 16 };
-static cl::opt<unsigned int>
-Radix("radix", cl::desc("Print size in radix. Only 8, 10, and 16 are valid"),
-      cl::init(decimal));
+static cl::opt<RadixTy> Radix(
+    "radix", cl::desc("Print size in radix"), cl::init(decimal),
+    cl::values(clEnumValN(octal, "8", "Print size in octal"),
+               clEnumValN(decimal, "10", "Print size in decimal"),
+               clEnumValN(hexadecimal, "16", "Print size in hexadecimal")));
 
 static cl::opt<RadixTy>
 RadixShort(cl::desc("Print size in radix:"),
@@ -865,7 +867,7 @@
   if (OutputFormatShort.getNumOccurrences())
     OutputFormat = static_cast<OutputFormatTy>(OutputFormatShort);
   if (RadixShort.getNumOccurrences())
-    Radix = RadixShort;
+    Radix = RadixShort.getValue();
 
   for (unsigned i = 0; i < ArchFlags.size(); ++i) {
     if (ArchFlags[i] == "all") {