diff --git a/git-compat-util.h b/git-compat-util.h
index f8e68baf29..9d3c21acbb 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -1150,70 +1150,7 @@ static inline size_t xsize_t(off_t len)
 #define HOST_NAME_MAX 256
 #endif
 
-/* in ctype.c, for kwset users */
-extern const unsigned char tolower_trans_tbl[256];
-
-/* Sane ctype - no locale, and works with signed chars */
-#undef isascii
-#undef isspace
-#undef isdigit
-#undef isalpha
-#undef isalnum
-#undef isprint
-#undef islower
-#undef isupper
-#undef tolower
-#undef toupper
-#undef iscntrl
-#undef ispunct
-#undef isxdigit
-
-extern const unsigned char sane_ctype[256];
-extern const signed char hexval_table[256];
-#define GIT_SPACE 0x01
-#define GIT_DIGIT 0x02
-#define GIT_ALPHA 0x04
-#define GIT_GLOB_SPECIAL 0x08
-#define GIT_REGEX_SPECIAL 0x10
-#define GIT_PATHSPEC_MAGIC 0x20
-#define GIT_CNTRL 0x40
-#define GIT_PUNCT 0x80
-#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
-#define isascii(x) (((x) & ~0x7f) == 0)
-#define isspace(x) sane_istest(x,GIT_SPACE)
-#define isdigit(x) sane_istest(x,GIT_DIGIT)
-#define isalpha(x) sane_istest(x,GIT_ALPHA)
-#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
-#define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
-#define islower(x) sane_iscase(x, 1)
-#define isupper(x) sane_iscase(x, 0)
-#define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
-#define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
-#define iscntrl(x) (sane_istest(x,GIT_CNTRL))
-#define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
-		GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
-#define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
-#define tolower(x) sane_case((unsigned char)(x), 0x20)
-#define toupper(x) sane_case((unsigned char)(x), 0)
-#define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
-
-static inline int sane_case(int x, int high)
-{
-	if (sane_istest(x, GIT_ALPHA))
-		x = (x & ~0x20) | high;
-	return x;
-}
-
-static inline int sane_iscase(int x, int is_lower)
-{
-	if (!sane_istest(x, GIT_ALPHA))
-		return 0;
-
-	if (is_lower)
-		return (x & 0x20) != 0;
-	else
-		return (x & 0x20) == 0;
-}
+#include "sane-ctype.h"
 
 /*
  * Like skip_prefix, but compare case-insensitively. Note that the comparison
diff --git a/sane-ctype.h b/sane-ctype.h
new file mode 100644
index 0000000000..df06bcbe14
--- /dev/null
+++ b/sane-ctype.h
@@ -0,0 +1,69 @@
+#ifndef SANE_CTYPE_H
+#define SANE_CTYPE_H
+
+/* in ctype.c, for kwset users */
+extern const unsigned char tolower_trans_tbl[256];
+
+/* Sane ctype - no locale, and works with signed chars */
+#undef isascii
+#undef isspace
+#undef isdigit
+#undef isalpha
+#undef isalnum
+#undef isprint
+#undef islower
+#undef isupper
+#undef tolower
+#undef toupper
+#undef iscntrl
+#undef ispunct
+#undef isxdigit
+
+extern const unsigned char sane_ctype[256];
+extern const signed char hexval_table[256];
+#define GIT_SPACE 0x01
+#define GIT_DIGIT 0x02
+#define GIT_ALPHA 0x04
+#define GIT_GLOB_SPECIAL 0x08
+#define GIT_REGEX_SPECIAL 0x10
+#define GIT_PATHSPEC_MAGIC 0x20
+#define GIT_CNTRL 0x40
+#define GIT_PUNCT 0x80
+#define sane_istest(x,mask) ((sane_ctype[(unsigned char)(x)] & (mask)) != 0)
+#define isascii(x) (((x) & ~0x7f) == 0)
+#define isspace(x) sane_istest(x,GIT_SPACE)
+#define isdigit(x) sane_istest(x,GIT_DIGIT)
+#define isalpha(x) sane_istest(x,GIT_ALPHA)
+#define isalnum(x) sane_istest(x,GIT_ALPHA | GIT_DIGIT)
+#define isprint(x) ((x) >= 0x20 && (x) <= 0x7e)
+#define islower(x) sane_iscase(x, 1)
+#define isupper(x) sane_iscase(x, 0)
+#define is_glob_special(x) sane_istest(x,GIT_GLOB_SPECIAL)
+#define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
+#define iscntrl(x) (sane_istest(x,GIT_CNTRL))
+#define ispunct(x) sane_istest(x, GIT_PUNCT | GIT_REGEX_SPECIAL | \
+		GIT_GLOB_SPECIAL | GIT_PATHSPEC_MAGIC)
+#define isxdigit(x) (hexval_table[(unsigned char)(x)] != -1)
+#define tolower(x) sane_case((unsigned char)(x), 0x20)
+#define toupper(x) sane_case((unsigned char)(x), 0)
+#define is_pathspec_magic(x) sane_istest(x,GIT_PATHSPEC_MAGIC)
+
+static inline int sane_case(int x, int high)
+{
+	if (sane_istest(x, GIT_ALPHA))
+		x = (x & ~0x20) | high;
+	return x;
+}
+
+static inline int sane_iscase(int x, int is_lower)
+{
+	if (!sane_istest(x, GIT_ALPHA))
+		return 0;
+
+	if (is_lower)
+		return (x & 0x20) != 0;
+	else
+		return (x & 0x20) == 0;
+}
+
+#endif
