diff --git a/include/strutils.h b/include/strutils.h
index 462332d95..99d8acd2c 100644
--- a/include/strutils.h
+++ b/include/strutils.h
@@ -7,6 +7,7 @@
 
 extern int strtosize(const char *str, uintmax_t *res);
 extern long strtol_or_err(const char *str, const char *errmesg);
+extern long long strtoll_or_err(const char *str, const char *errmesg);
 
 #ifndef HAVE_STRNLEN
 extern size_t strnlen(const char *s, size_t maxlen);
diff --git a/lib/strutils.c b/lib/strutils.c
index 39c9bdf02..acb7139dc 100644
--- a/lib/strutils.c
+++ b/lib/strutils.c
@@ -188,6 +188,30 @@ err:
                errx(EXIT_FAILURE, "%s: '%s'", errmesg, str);
        return 0;
 }
+/*
+ * same as strtoll(3) but exit on failure instead of returning crap
+ */
+long long strtoll_or_err(const char *str, const char *errmesg)
+{
+       long long num;
+       char *end = NULL;
+
+       if (str == NULL || *str == '\0')
+               goto err;
+       errno = 0;
+       num = strtoll(str, &end, 10);
+
+       if (errno || (end && *end))
+               goto err;
+
+       return num;
+err:
+       if (errno)
+               err(EXIT_FAILURE, "%s: '%s'", errmesg, str);
+       else
+               errx(EXIT_FAILURE, "%s: '%s'", errmesg, str);
+       return 0;
+}
 
 /*
  * Converts stat->st_mode to ls(1)-like mode string. The size of "str" must