diff --git a/src/signal.rs b/src/signal.rs
index 867a12d..5a8dd47 100644
--- a/src/signal.rs
+++ b/src/signal.rs
@@ -53,10 +53,11 @@ pub fn install_handler<F>(handler: F)
 
             let mut new_mask = SigSet::empty();
             new_mask.add(raw_signal);
-            let _ = new_mask.thread_unblock();
 
-            // Re-raise
+            // Re-raise with signal unmasked
+            let _ = new_mask.thread_unblock();
             let _ = raise(raw_signal);
+            let _ = new_mask.thread_block();
         }
     });
 }
diff --git a/test/print_hi.py b/test/print_hi.py
new file mode 100644
index 0000000..31bb6ad
--- /dev/null
+++ b/test/print_hi.py
@@ -0,0 +1,5 @@
+import time
+
+while True:
+    print "hi"
+    time.sleep(1)