diff --git a/src/connection.h b/src/connection.h
index 2e2da2d..6a548ce 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -5,6 +5,9 @@
 #include <stdint.h>
 #include <stdlib.h>
 
+// not really connectiony, but need per-platform
+int GetProcessId();
+
 struct BaseConnection {
     static BaseConnection* Create();
     static void Destroy(BaseConnection*&);
diff --git a/src/connection_unix.cpp b/src/connection_unix.cpp
index fbf5a23..50e5199 100644
--- a/src/connection_unix.cpp
+++ b/src/connection_unix.cpp
@@ -1,5 +1,13 @@
 #include "connection.h"
 
+#include <sys/types.h>
+#include <unistd.h>
+
+int GetProcessId()
+{
+    return ::getpid();
+}
+
 const int RpcVersion = 1;
 const int NumFrames = 4;
 
diff --git a/src/connection_win.cpp b/src/connection_win.cpp
index 1a5a445..9497170 100644
--- a/src/connection_win.cpp
+++ b/src/connection_win.cpp
@@ -6,6 +6,11 @@
 #define NOIME
 #include <windows.h>
 
+int GetProcessId()
+{
+    return ::GetCurrentProcessId();
+}
+
 struct BaseConnectionWin : public BaseConnection {
     HANDLE pipe{INVALID_HANDLE_VALUE};
 };