diff --git a/include/QF/dstring.h b/include/QF/dstring.h
index e43bb1055..0f03f720a 100644
--- a/include/QF/dstring.h
+++ b/include/QF/dstring.h
@@ -52,6 +52,7 @@ void dstring_clear (dstring_t *dstr);
 // String-specific functions
 dstring_t *dstring_newstr (void);
 void dstring_appendstr (dstring_t *dstr, const char *str);
+void dstring_appendsubstr (dstring_t *dstr, const char *str, unsigned int len);
 void dstring_insertstr (dstring_t *dstr, const char *str, unsigned int pos);
 void dstring_clearstr (dstring_t *dstr);
 
diff --git a/libs/util/dstring.c b/libs/util/dstring.c
index 0ebeb2673..1914c857b 100644
--- a/libs/util/dstring.c
+++ b/libs/util/dstring.c
@@ -123,6 +123,15 @@ dstring_appendstr (dstring_t *dstr, const char *str) {
 		strcat(dstr->str, str);
 }
 
+void
+dstring_appendsubstr (dstring_t *dstr, const char *str, unsigned int len) {
+		if (len > strlen (str))
+			len = strlen (str);
+		dstr->size += len;
+		dstring_adjust(dstr);
+		strncat(dstr->str, str, len);
+}
+
 void
 dstring_insertstr (dstring_t *dstr, const char *str, unsigned int pos)
 {