diff --git a/src/libmain/stack.cc b/src/libmain/stack.cc
index 0ea80f18e..64df95547 100644
--- a/src/libmain/stack.cc
+++ b/src/libmain/stack.cc
@@ -53,7 +53,7 @@ void detectStackOverflow()
        requires an alternative stack, otherwise the signal cannot be
        delivered when we're out of stack space. */
     stack_t stack;
-    stack.ss_size = 4096 * 4;
+    stack.ss_size = 4096 * 4 + MINSIGSTKSZ;
     stack.ss_sp = new char[stack.ss_size];
     if (!stack.ss_sp) throw Error("cannot allocate alternative stack");
     stack.ss_flags = 0;