diff --git a/.gitignore b/.gitignore
index 5afcdc4..68c2ff4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -41,3 +41,7 @@ build/
 cmake-build-*/
 __pycache__/
 dsdlc_generated/
+
+# OS stuff
+.DS_Store
+*.bak
diff --git a/socketcan/libcanard/src/socketcan.c b/socketcan/libcanard/src/socketcan.c
index 3ff2a12..fd369ca 100644
--- a/socketcan/libcanard/src/socketcan.c
+++ b/socketcan/libcanard/src/socketcan.c
@@ -30,7 +30,7 @@
 #define KILO 1000L
 #define MEGA (KILO * KILO)
 
-static int16_t getNegatedErrno()
+static int16_t getNegatedErrno(void)
 {
     const int out = -abs(errno);
     if (out < 0)