diff --git a/lldb/source/Target/Platform.cpp b/lldb/source/Target/Platform.cpp
index bd03fa7ec1eb..0ed2b510fb03 100644
--- a/lldb/source/Target/Platform.cpp
+++ b/lldb/source/Target/Platform.cpp
@@ -10,6 +10,7 @@
 // C Includes
 // C++ Includes
 #include <algorithm>
+#include <csignal>
 #include <fstream>
 #include <vector>