diff --git a/Sources/_SubprocessCShims/process_shims.c b/Sources/_SubprocessCShims/process_shims.c
index 9d4837de..8fd234bb 100644
--- a/Sources/_SubprocessCShims/process_shims.c
+++ b/Sources/_SubprocessCShims/process_shims.c
@@ -30,7 +30,6 @@
 #include <unistd.h>
 #include <grp.h>
 #include <signal.h>
-#include <signal.h>
 #include <string.h>
 #include <fcntl.h>
 #include <pthread.h>