diff --git a/lib/Bitcode/Reader/BitcodeReader.h b/lib/Bitcode/Reader/BitcodeReader.h
index c5e97991b92..3d5c0eb4def 100644
--- a/lib/Bitcode/Reader/BitcodeReader.h
+++ b/lib/Bitcode/Reader/BitcodeReader.h
@@ -180,7 +180,7 @@ class BitcodeReader : public GVMaterializer {
   DenseMap<Function*, std::vector<BlockAddrRefTy> > BlockAddrFwdRefs;
 
   /// UseRelativeIDs - Indicates that we are using a new encoding for
-  /// instrunction operands where most operands in the current
+  /// instruction operands where most operands in the current
   /// FUNCTION_BLOCK are encoded relative to the instruction number,
   /// for a more compact encoding.  Some instruction operands are not
   /// relative to the instruction ID: basic block numbers, and types.
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index efa60b8e076..60c657ae6dd 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1552,7 +1552,7 @@ static void WriteFunction(const Function &F, ValueEnumerator &VE,
 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
   // We only want to emit block info records for blocks that have multiple
   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
-  // Other blocks can defined their abbrevs inline.
+  // Other blocks can define their abbrevs inline.
   Stream.EnterBlockInfoBlock(2);
 
   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.