diff --git a/clang/include/clang/Basic/FPOptions.def b/clang/include/clang/Basic/FPOptions.def
index 79f04c89c9fed..90428c3c73c8b 100644
--- a/clang/include/clang/Basic/FPOptions.def
+++ b/clang/include/clang/Basic/FPOptions.def
@@ -28,5 +28,5 @@ OPTION(FPEvalMethod, LangOptions::FPEvalMethodKind, 2, AllowApproxFunc)
 OPTION(Float16ExcessPrecision, LangOptions::ExcessPrecisionKind, 2, FPEvalMethod)
 OPTION(BFloat16ExcessPrecision, LangOptions::ExcessPrecisionKind, 2, Float16ExcessPrecision)
 OPTION(MathErrno, bool, 1, BFloat16ExcessPrecision)
-OPTION(ComplexRange, LangOptions::ComplexRangeKind, 2, MathErrno)
+OPTION(ComplexRange, LangOptions::ComplexRangeKind, 3, MathErrno)
 #undef OPTION
diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def
index cb55f09acc076..bfab0baa089cf 100644
--- a/clang/include/clang/Basic/LangOptions.def
+++ b/clang/include/clang/Basic/LangOptions.def
@@ -238,7 +238,7 @@ BENIGN_LANGOPT(NoSignedZero      , 1, 0, "Permit Floating Point optimization wit
 BENIGN_LANGOPT(AllowRecip        , 1, 0, "Permit Floating Point reciprocal")
 BENIGN_LANGOPT(ApproxFunc        , 1, 0, "Permit Floating Point approximation")
 
-ENUM_LANGOPT(ComplexRange, ComplexRangeKind, 2, CX_None, "Enable use of range reduction for complex arithmetics.")
+ENUM_LANGOPT(ComplexRange, ComplexRangeKind, 3, CX_None, "Enable use of range reduction for complex arithmetics.")
 
 BENIGN_LANGOPT(ObjCGCBitmapPrint , 1, 0, "printing of GC's bitmap layout for __weak/__strong ivars")
 
diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
index f58a719a45a84..651b3b67b1058 100644
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -648,9 +648,12 @@ class LangOptions : public LangOptionsBase {
 
   // Define accessors/mutators for language options of enumeration type.
 #define LANGOPT(Name, Bits, Default, Description)
-#define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
-  Type get##Name() const { return static_cast<Type>(Name); } \
-  void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
+#define ENUM_LANGOPT(Name, Type, Bits, Default, Description)                   \
+  Type get##Name() const { return static_cast<Type>(Name); }                   \
+  void set##Name(Type Value) {                                                 \
+    assert(static_cast<unsigned>(Value) < (1u << Bits));                       \
+    Name = static_cast<unsigned>(Value);                                       \
+  }
 #include "clang/Basic/LangOptions.def"
 
   /// Are we compiling a module?
@@ -959,11 +962,14 @@ class FPOptions {
   void applyChanges(FPOptionsOverride FPO);
 
   // We can define most of the accessors automatically:
+  // TODO: consider enforcing the assertion that value fits within bits
+  // statically.
 #define OPTION(NAME, TYPE, WIDTH, PREVIOUS)                                    \
   TYPE get##NAME() const {                                                     \
     return static_cast<TYPE>((Value & NAME##Mask) >> NAME##Shift);             \
   }                                                                            \
   void set##NAME(TYPE value) {                                                 \
+    assert(storage_type(value) < (1u << WIDTH));                               \
     Value = (Value & ~NAME##Mask) | (storage_type(value) << NAME##Shift);      \
   }
 #include "clang/Basic/FPOptions.def"