diff --git a/debuggerd/signal_sender.cpp b/debuggerd/signal_sender.cpp
index 35e0c0b..1cfb704 100644
--- a/debuggerd/signal_sender.cpp
+++ b/debuggerd/signal_sender.cpp
@@ -37,7 +37,7 @@
 
 // Fork a process to send signals for the worker processes to use after they've dropped privileges.
 bool start_signal_sender() {
-  if (signal_pid == 0) {
+  if (signal_pid != 0) {
     ALOGE("debuggerd: attempted to start signal sender multiple times");
     return false;
   }