diff --git a/compiler/optimizing/constant_folding.cc b/compiler/optimizing/constant_folding.cc
index 20ce110..e0aa4ff 100644
--- a/compiler/optimizing/constant_folding.cc
+++ b/compiler/optimizing/constant_folding.cc
@@ -226,14 +226,14 @@
 
   // We assume that GVN has run before, so we only perform a pointer
   // comparison.  If for some reason the values are equal but the pointers are
-  // different, we are still correct and only miss an optimisation
+  // different, we are still correct and only miss an optimization
   // opportunity.
   if (instruction->GetLeft() == instruction->GetRight()) {
     // Replace code looking like
     //    SUB dst, src, src
     // with
     //    CONSTANT 0
-    // Note that we cannot optimise `x - x` to `0` for floating-point. It does
+    // Note that we cannot optimize `x - x` to `0` for floating-point. It does
     // not work when `x` is an infinity.
     instruction->ReplaceWith(GetGraph()->GetConstant(type, 0));
     block->RemoveInstruction(instruction);
diff --git a/runtime/arch/mips/memcmp16_mips.S b/runtime/arch/mips/memcmp16_mips.S
index aef81af..c8eac9b 100644
--- a/runtime/arch/mips/memcmp16_mips.S
+++ b/runtime/arch/mips/memcmp16_mips.S
@@ -26,7 +26,7 @@
   beqz  $a2,done   /* 0 length string */
   beq $a0,$a1,done    /* strings are identical */
 
-  /* Unoptimised... */
+  /* Unoptimized... */
 1:  lhu $t0,0($a0)
   lhu $t1,0($a1)
   addu  $a1,2