diff --git a/sandboxed_api/sandbox2/policybuilder.cc b/sandboxed_api/sandbox2/policybuilder.cc
index fd1cb92..671bd69 100644
--- a/sandboxed_api/sandbox2/policybuilder.cc
+++ b/sandboxed_api/sandbox2/policybuilder.cc
@@ -184,6 +184,9 @@ PolicyBuilder& PolicyBuilder::AllowLlvmSanitizers() {
   // Sanitizers read from /proc. For example:
   // https://github.com/llvm-mirror/compiler-rt/blob/69445f095c22aac2388f939bedebf224a6efcdaf/lib/sanitizer_common/sanitizer_linux.cpp#L1101
   AddDirectory("/proc");
+#endif
+#if defined(ADDRESS_SANITIZER)
+  AllowSyscall(__NR_sigaltstack);
 #endif
   return *this;
 }
@@ -347,6 +350,9 @@ PolicyBuilder& PolicyBuilder::AllowHandleSignals() {
 #endif
 #ifdef __NR_sigprocmask
       __NR_sigprocmask,
+#endif
+#ifdef __NR_sigaltstack
+      __NR_sigaltstack,
 #endif
   });
 }