diff --git a/dir.c b/dir.c
index 133f472a1e..4d001fd632 100644
--- a/dir.c
+++ b/dir.c
@@ -18,6 +18,22 @@ static int read_directory_recursive(struct dir_struct *dir, const char *path, in
 	int check_only, const struct path_simplify *simplify);
 static int get_dtype(struct dirent *de, const char *path, int len);
 
+/* helper string functions with support for the ignore_case flag */
+int strcmp_icase(const char *a, const char *b)
+{
+	return ignore_case ? strcasecmp(a, b) : strcmp(a, b);
+}
+
+int strncmp_icase(const char *a, const char *b, size_t count)
+{
+	return ignore_case ? strncasecmp(a, b, count) : strncmp(a, b, count);
+}
+
+int fnmatch_icase(const char *pattern, const char *string, int flags)
+{
+	return fnmatch(pattern, string, flags | (ignore_case ? FNM_CASEFOLD : 0));
+}
+
 static int common_prefix(const char **pathspec)
 {
 	const char *path, *slash, *next;
diff --git a/dir.h b/dir.h
index 278d84cdf7..b3e2104b9f 100644
--- a/dir.h
+++ b/dir.h
@@ -101,4 +101,8 @@ extern int remove_dir_recursively(struct strbuf *path, int flag);
 /* tries to remove the path with empty directories along it, ignores ENOENT */
 extern int remove_path(const char *path);
 
+extern int strcmp_icase(const char *a, const char *b);
+extern int strncmp_icase(const char *a, const char *b, size_t count);
+extern int fnmatch_icase(const char *pattern, const char *string, int flags);
+
 #endif