diff --git a/lib/roken/parse_units.c b/lib/roken/parse_units.c
index d76578abf..017eedf37 100644
--- a/lib/roken/parse_units.c
+++ b/lib/roken/parse_units.c
@@ -275,8 +275,7 @@ acc_flags(uint64_t res, int64_t val, uint64_t mult)
 }
 
 ROKEN_LIB_FUNCTION uint64_t ROKEN_LIB_CALL
-parse_flags (const char *s, const struct units *units,
-	     int orig)
+parse_flags(const char *s, const struct units *units, uint64_t orig)
 {
     return parse_something_unsigned (s, units, NULL, acc_flags, orig, 1);
 }
diff --git a/lib/roken/parse_units.h b/lib/roken/parse_units.h
index c5b6f2030..d17897dda 100644
--- a/lib/roken/parse_units.h
+++ b/lib/roken/parse_units.h
@@ -97,8 +97,8 @@ ROKEN_LIB_FUNCTION void ROKEN_LIB_CALL
 print_units_table (const struct units *units, FILE *f);
 
 ROKEN_LIB_FUNCTION uint64_t ROKEN_LIB_CALL
-parse_flags (const char *s, const struct units *units,
-	     int orig);
+parse_flags(const char *s, const struct units *units,
+	    uint64_t orig);
 
 ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
 unparse_units(int64_t num, const struct units *units, char *s, size_t len);