diff --git a/src/processor/stackwalker.cc b/src/processor/stackwalker.cc
index cba604e6..00eaa6af 100644
--- a/src/processor/stackwalker.cc
+++ b/src/processor/stackwalker.cc
@@ -139,6 +139,9 @@ Stackwalker* Stackwalker::StackwalkerForCPU(
     const CodeModules *modules,
     SymbolSupplier *supplier,
     SourceLineResolverInterface *resolver) {
+  if (!context)
+    return NULL;
+
   Stackwalker *cpu_stackwalker = NULL;
 
   u_int32_t cpu = context->GetContextCPU();