diff --git a/ctype.c b/ctype.c
index de600279ee..b5d856fd26 100644
--- a/ctype.c
+++ b/ctype.c
@@ -10,17 +10,18 @@ enum {
 	A = GIT_ALPHA,
 	D = GIT_DIGIT,
 	G = GIT_GLOB_SPECIAL,	/* *, ?, [, \\ */
-	R = GIT_REGEX_SPECIAL	/* $, (, ), +, ., ^, {, | */
+	R = GIT_REGEX_SPECIAL,	/* $, (, ), +, ., ^, {, | */
+	P = GIT_PATHSPEC_MAGIC  /* other non-alnum, except for ] and } */
 };
 
 unsigned char sane_ctype[256] = {
 	0, 0, 0, 0, 0, 0, 0, 0, 0, S, S, 0, 0, S, 0, 0,		/*   0.. 15 */
 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,		/*  16.. 31 */
-	S, 0, 0, 0, R, 0, 0, 0, R, R, G, R, 0, 0, R, 0,		/*  32.. 47 */
-	D, D, D, D, D, D, D, D, D, D, 0, 0, 0, 0, 0, G,		/*  48.. 63 */
-	0, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A,		/*  64.. 79 */
-	A, A, A, A, A, A, A, A, A, A, A, G, G, 0, R, 0,		/*  80.. 95 */
-	0, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A,		/*  96..111 */
-	A, A, A, A, A, A, A, A, A, A, A, R, R, 0, 0, 0,		/* 112..127 */
+	S, P, P, P, R, P, P, P, R, R, G, R, P, P, R, P,		/*  32.. 47 */
+	D, D, D, D, D, D, D, D, D, D, P, P, P, P, P, G,		/*  48.. 63 */
+	P, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A,		/*  64.. 79 */
+	A, A, A, A, A, A, A, A, A, A, A, G, G, 0, R, P,		/*  80.. 95 */
+	P, A, A, A, A, A, A, A, A, A, A, A, A, A, A, A,		/*  96..111 */
+	A, A, A, A, A, A, A, A, A, A, A, R, R, 0, P, 0,		/* 112..127 */
 	/* Nothing in the 128.. range */
 };
diff --git a/git-compat-util.h b/git-compat-util.h
index 49b50eec86..d88cf8afb6 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -462,6 +462,7 @@ extern unsigned char sane_ctype[256];
 #define GIT_ALPHA 0x04
 #define GIT_GLOB_SPECIAL 0x08
 #define GIT_REGEX_SPECIAL 0x10
+#define GIT_PATHSPEC_MAGIC 0x20
 #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)
@@ -472,6 +473,7 @@ extern unsigned char sane_ctype[256];
 #define is_regex_special(x) sane_istest(x,GIT_GLOB_SPECIAL | GIT_REGEX_SPECIAL)
 #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)
 {
diff --git a/setup.c b/setup.c
index 820ed05b27..5048252d78 100644
--- a/setup.c
+++ b/setup.c
@@ -197,19 +197,26 @@ const char *prefix_pathspec(const char *prefix, int prefixlen, const char *elt)
 		}
 		if (*copyfrom == ')')
 			copyfrom++;
+	} else if (!elt[1]) {
+		/* Just ':' -- no element! */
+		return NULL;
 	} else {
 		/* shorthand */
 		for (copyfrom = elt + 1;
 		     *copyfrom && *copyfrom != ':';
 		     copyfrom++) {
 			char ch = *copyfrom;
+
+			if (!is_pathspec_magic(ch))
+				break;
 			for (i = 0; i < ARRAY_SIZE(pathspec_magic); i++)
 				if (pathspec_magic[i].mnemonic == ch) {
 					magic |= pathspec_magic[i].bit;
 					break;
 				}
 			if (ARRAY_SIZE(pathspec_magic) <= i)
-				break;
+				die("Unimplemented pathspec magic '%c' in '%s'",
+				    ch, elt);
 		}
 		if (*copyfrom == ':')
 			copyfrom++;