diff --git a/femtolisp/print.c b/femtolisp/print.c
index 670d333..955c6a9 100644
--- a/femtolisp/print.c
+++ b/femtolisp/print.c
@@ -375,6 +375,7 @@ void fl_print_child(ios_t *f, value_t v, int princ)
         break;
     case TAG_CVALUE:
     case TAG_CPRIM:
+      if (v == UNBOUND) { HPOS+=ios_printf(f, "#<undefined>"); break; }
     case TAG_VECTOR:
     case TAG_CONS:
         if ((label=(value_t)ptrhash_get(&printconses, (void*)v)) !=
diff --git a/femtolisp/read.c b/femtolisp/read.c
index 32c331a..3ef5dbe 100644
--- a/femtolisp/read.c
+++ b/femtolisp/read.c
@@ -26,7 +26,8 @@ static int isnumtok_base(char *tok, value_t *pval, int base)
     double d;
     if (*tok == '\0')
         return 0;
-    if (strpbrk(tok, ".eEpP")) {
+    if (!((tok[0]=='0' && tok[1]=='x') || (base >= 15)) &&
+        strpbrk(tok, ".eEpP")) {
         d = strtod(tok, &end);
         if (*end == '\0') {
             if (pval) *pval = mk_double(d);