diff --git a/newlib/libc/tinystdio/conv_flt.c b/newlib/libc/tinystdio/conv_flt.c
index de16032b0d..b309e29ac2 100644
--- a/newlib/libc/tinystdio/conv_flt.c
+++ b/newlib/libc/tinystdio/conv_flt.c
@@ -394,8 +394,12 @@ conv_flt (FLT_STREAM *stream, FLT_CONTEXT *context, width_t width, void *addr, u
 	    if (!isdigit (edig))
             {
                 scanf_ungetc(edig, stream, context);
-                if (esign != EOF)
-                    scanf_ungetc(esign, stream, context);
+                if (esign != EOF) {
+                    esign = scanf_getc (stream, context);
+                    if(!isdigit (esign))
+                        return 0;
+                    scanf_ungetc(edig, stream, context);
+                    }
                 goto no_exp;
             }
 
diff --git a/newlib/libc/tinystdio/vfscanf.c b/newlib/libc/tinystdio/vfscanf.c
index 7ae6c49fd2..98aba552a9 100644
--- a/newlib/libc/tinystdio/vfscanf.c
+++ b/newlib/libc/tinystdio/vfscanf.c
@@ -279,6 +279,8 @@ conv_int (FILE *stream, scanf_context_t *context, width_t width, void *addr, uin
             base = 16;
             if (!--width || IS_EOF(i = scanf_getc (stream, context)))
 		goto putval;
+            if(!isxdigit(i))
+                goto err;
 #ifdef _NEED_IO_PERCENT_B
         } else if (i == 'b' && base <= 2) {
             base = 2;