diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index b621e51..8a5077b 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -79,13 +79,14 @@
                                                jobject class_loader,
                                                const DexFile& dex_file) const {
   InstructionSet instruction_set = GetCompilerDriver()->GetInstructionSet();
-  // The optimizing compiler currently does not have a Thumb2 assembler.
-  if (instruction_set == kThumb2) {
-    instruction_set = kArm;
+  // Always use the thumb2 assembler: some runtime functionality (like implicit stack
+  // overflow checks) assume thumb2.
+  if (instruction_set == kArm) {
+    instruction_set = kThumb2;
   }
 
   // Do not attempt to compile on architectures we do not support.
-  if (instruction_set != kX86 && instruction_set != kX86_64 && instruction_set != kArm) {
+  if (instruction_set != kX86 && instruction_set != kX86_64 && instruction_set != kThumb2) {
     return nullptr;
   }