diff --git a/compat/precompose_utf8.c b/compat/precompose_utf8.c
index ec560565a8..cce1d57a46 100644
--- a/compat/precompose_utf8.c
+++ b/compat/precompose_utf8.c
@@ -60,10 +60,12 @@ void probe_utf8_pathname_composition(void)
 	strbuf_release(&path);
 }
 
-static inline const char *precompose_string_if_needed(const char *in)
+const char *precompose_string_if_needed(const char *in)
 {
 	size_t inlen;
 	size_t outlen;
+	if (!in)
+		return NULL;
 	if (has_non_ascii(in, (size_t)-1, &inlen)) {
 		iconv_t ic_prec;
 		char *out;
@@ -96,10 +98,7 @@ const char *precompose_argv_prefix(int argc, const char **argv, const char *pref
 		argv[i] = precompose_string_if_needed(argv[i]);
 		i++;
 	}
-	if (prefix) {
-		prefix = precompose_string_if_needed(prefix);
-	}
-	return prefix;
+	return precompose_string_if_needed(prefix);
 }
 
 
diff --git a/compat/precompose_utf8.h b/compat/precompose_utf8.h
index d70b84665c..fea06cf28a 100644
--- a/compat/precompose_utf8.h
+++ b/compat/precompose_utf8.h
@@ -29,6 +29,7 @@ typedef struct {
 } PREC_DIR;
 
 const char *precompose_argv_prefix(int argc, const char **argv, const char *prefix);
+const char *precompose_string_if_needed(const char *in);
 void probe_utf8_pathname_composition(void);
 
 PREC_DIR *precompose_utf8_opendir(const char *dirname);
diff --git a/git-compat-util.h b/git-compat-util.h
index 93d9b4b7af..3616d12d47 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -256,6 +256,11 @@ static inline const char *precompose_argv_prefix(int argc, const char **argv, co
 {
 	return prefix;
 }
+static inline const char *precompose_string_if_needed(const char *in)
+{
+	return in;
+}
+
 #define probe_utf8_pathname_composition()
 #endif