diff --git a/skeletons/NativeReal.c b/skeletons/NativeReal.c
index da1bed7..1dc1f71 100644
--- a/skeletons/NativeReal.c
+++ b/skeletons/NativeReal.c
@@ -109,6 +109,7 @@
     rval = ber_check_tags(opt_codec_ctx, td, 0, buf_ptr, size, tag_mode, 0,
                           &length, 0);
     if(rval.code != RC_OK) return rval;
+    assert(length >= 0);    /* Ensured by ber_check_tags */
 
     ASN_DEBUG("%s length is %d bytes", td->name, (int)length);
 
@@ -134,7 +135,7 @@
         double d;
         int ret;
 
-        if(length < sizeof(scratch)) {
+        if((size_t)length < sizeof(scratch)) {
             tmp.buf = scratch;
             tmp.size = length;
         } else {
@@ -520,7 +521,10 @@
         -4503599627370496.0, 4503599627370496.0,
         /* 2^100 */
         -1267650600228229401496703205376.0, 1267650600228229401496703205376.0,
-        -MAXFLOAT, MAXFLOAT, INFINITY, -INFINITY, NAN};
+#if __STDC_VERSION__ >= 199901L
+        -MAXFLOAT, MAXFLOAT,
+#endif
+        INFINITY, -INFINITY, NAN};
     double *st;
     double d;