diff --git a/compiler/trampolines/trampoline_compiler.cc b/compiler/trampolines/trampoline_compiler.cc
index 24378b4..ac84d6a 100644
--- a/compiler/trampolines/trampoline_compiler.cc
+++ b/compiler/trampolines/trampoline_compiler.cc
@@ -30,6 +30,10 @@
 namespace arm {
 static const std::vector<uint8_t>* CreateTrampoline(EntryPointCallingConvention abi,
                                                     ThreadOffset<4> offset) {
+  // NOTE: the assembler used here is ARM, not Thumb.  This is because the address
+  // returned by this function is a pointer and for thumb we would have to set the
+  // bottom bit.  It doesn't matter since the instructions generated are the same
+  // size anyway.
   std::unique_ptr<ArmAssembler> assembler(static_cast<ArmAssembler*>(Assembler::Create(kArm)));
 
   switch (abi) {