diff --git a/git-compat-util.h b/git-compat-util.h
index dfaf5fff31..ddafec997f 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -375,6 +375,7 @@ static inline int strtoul_ui(char const *s, int base, unsigned int *result)
 #ifndef S_ISLNK
 #define S_IFLNK    0120000 /* Symbolic link */
 #define S_ISLNK(x) (((x) & S_IFMT) == S_IFLNK)
+#define S_ISSOCK(x) 0
 #endif
 
 #ifndef S_ISGRP