diff --git a/git-compat-util.h b/git-compat-util.h
index 7059cbdab7..b6ef5442b7 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -122,6 +122,8 @@ extern void set_die_routine(void (*routine)(const char *err, va_list params) NOR
 extern void set_error_routine(void (*routine)(const char *err, va_list params));
 extern void set_warn_routine(void (*routine)(const char *warn, va_list params));
 
+extern int prefixcmp(const char *str, const char *prefix);
+
 #ifdef NO_MMAP
 
 #ifndef PROT_READ
@@ -396,15 +398,6 @@ static inline int sane_case(int x, int high)
 	return x;
 }
 
-static inline int prefixcmp(const char *str, const char *prefix)
-{
-	for (; ; str++, prefix++)
-		if (!*prefix)
-			return 0;
-		else if (*str != *prefix)
-			return (unsigned char)*prefix - (unsigned char)*str;
-}
-
 static inline int strtoul_ui(char const *s, int base, unsigned int *result)
 {
 	unsigned long ul;
diff --git a/strbuf.c b/strbuf.c
index b9b194b320..5efcfc8860 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,5 +1,14 @@
 #include "cache.h"
 
+int prefixcmp(const char *str, const char *prefix)
+{
+	for (; ; str++, prefix++)
+		if (!*prefix)
+			return 0;
+		else if (*str != *prefix)
+			return (unsigned char)*prefix - (unsigned char)*str;
+}
+
 /*
  * Used as the default ->buf value, so that people can always assume
  * buf is non NULL and ->buf is NUL terminated even for a freshly