diff --git a/runtime/signal_set.h b/runtime/signal_set.h
index c272514..6f88852 100644
--- a/runtime/signal_set.h
+++ b/runtime/signal_set.h
@@ -38,8 +38,8 @@
   }
 
   void Block() {
-    if (sigprocmask(SIG_BLOCK, &set_, nullptr) == -1) {
-      PLOG(FATAL) << "sigprocmask failed";
+    if (pthread_sigmask(SIG_BLOCK, &set_, nullptr) != 0) {
+      PLOG(FATAL) << "pthread_sigmask failed";
     }
   }
 
diff --git a/test/004-ThreadStress/src/Main.java b/test/004-ThreadStress/src/Main.java
index b9a46de..acd8e8b 100644
--- a/test/004-ThreadStress/src/Main.java
+++ b/test/004-ThreadStress/src/Main.java
@@ -107,6 +107,7 @@
         public boolean perform() {
             try {
                 kill.invoke(null, pid, sigquit);
+            } catch (OutOfMemoryError e) {
             } catch (Exception e) {
                 if (!e.getClass().getName().equals("ErrnoException")) {
                     e.printStackTrace(System.out);
@@ -154,7 +155,10 @@
     private final static class StackTrace extends Operation {
         @Override
         public boolean perform() {
-            Thread.currentThread().getStackTrace();
+            try {
+                Thread.currentThread().getStackTrace();
+            } catch (OutOfMemoryError e) {
+            }
             return true;
         }
     }