diff --git a/src/libsysprof/sysprof-proxy-source.c b/src/libsysprof/sysprof-proxy-source.c
index 61e6d59b..f686a19b 100644
--- a/src/libsysprof/sysprof-proxy-source.c
+++ b/src/libsysprof/sysprof-proxy-source.c
@@ -22,6 +22,7 @@
 
 #include "config.h"
 
+#include <errno.h>
 #include <gio/gunixfdlist.h>
 #include <sysprof.h>