diff --git a/runtime/thread.cc b/runtime/thread.cc
index f1f4a12..53b9836 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -924,10 +924,22 @@
 
   Runtime* runtime = Runtime::Current();
   bool implicit_stack_check = !runtime->ExplicitStackOverflowChecks() && !runtime->IsAotCompiler();
+
+  // Valgrind on arm doesn't give the right values here. Do not install the guard page, and
+  // effectively disable stack overflow checks (we'll get segfaults, potentially) by setting
+  // stack_begin to 0.
+  const bool valgrind_on_arm =
+      (kRuntimeISA == kArm || kRuntimeISA == kArm64) &&
+      kMemoryToolIsValgrind &&
+      RUNNING_ON_MEMORY_TOOL != 0;
+  if (valgrind_on_arm) {
+    tlsPtr_.stack_begin = nullptr;
+  }
+
   ResetDefaultStackEnd();
 
   // Install the protected region if we are doing implicit overflow checks.
-  if (implicit_stack_check) {
+  if (implicit_stack_check && !valgrind_on_arm) {
     // The thread might have protected region at the bottom.  We need
     // to install our own region so we need to move the limits
     // of the stack to make room for it.