diff --git a/Shell/Builtin.cpp b/Shell/Builtin.cpp
index 6e2a8e89a4..fb2734b3e4 100644
--- a/Shell/Builtin.cpp
+++ b/Shell/Builtin.cpp
@@ -31,7 +31,9 @@
 #include <inttypes.h>
 #include <signal.h>
 #include <sys/wait.h>
+#include <unistd.h>
 
+extern char** environ;
 extern RefPtr<Line::Editor> editor;
 
 int Shell::builtin_alias(int argc, const char** argv)
diff --git a/Shell/Shell.cpp b/Shell/Shell.cpp
index cd22875052..4909b3e8b9 100644
--- a/Shell/Shell.cpp
+++ b/Shell/Shell.cpp
@@ -52,6 +52,7 @@
 
 static bool s_disable_hyperlinks = false;
 extern RefPtr<Line::Editor> editor;
+extern char** environ;
 
 //#define SH_DEBUG