diff --git a/reader.c b/reader.c
index fb74605..5b5d974 100644
--- a/reader.c
+++ b/reader.c
@@ -342,29 +342,24 @@ static value_t read_number(reader_state_t *state)
     {
     case 'X':
     case 'x':
-      next_char(state);
       radix = 16;
+      next_char(state);
       break;
     case 'B':
     case 'b':
-      next_char(state);
       radix = 2;
+      next_char(state);
       break;
     case '0' ... '9':
-      ungetc(state->ch, state->file);
-      state->ch = '0';
       radix = 8;
       break;
     default:
-      ungetc(state->ch, state->file);
-      state->ch = '0';
       radix = 10;
       break;
     }
 
-    if (radix != 8)
+    if (radix != 10)
     {
-      /* Make sure we have at least one digit; if octal then the '0' counts instead */
       release_assert(isalnum(state->ch));
       release_assert(char_to_digit(state->ch) < radix);
     }