diff --git a/lib/asn1/gen_encode.c b/lib/asn1/gen_encode.c
index b0123a8be..50fb9ddfe 100644
--- a/lib/asn1/gen_encode.c
+++ b/lib/asn1/gen_encode.c
@@ -551,15 +551,15 @@ encode_type (const char *name, const Type *t, const char *tmpstr)
                      *                \
                      *                 +-- psave_<fieldName>
                      */
-                    "e = der_put_tag(psave_%s, %lu, %s, %s, %d, &l2_%s);\n"
+                    "e = der_put_tag(psave_%s, %zu, %s, %s, %d, &l2_%s);\n"
                     "if (e) return e;\n"
                     /* Restore `len' and adjust it (see `p' below) */
-                    "len = lensave_%s - (l + %lu - asn1_tag_length_%s);\n"
+                    "len = lensave_%s - (l + %zu - asn1_tag_length_%s);\n"
                     /*
                      * Adjust `ret' to account for the difference in size
                      * between the length of the right and wrong tags.
                      */
-                    "ret += %lu - asn1_tag_length_%s;\n"
+                    "ret += %zu - asn1_tag_length_%s;\n"
                     /* Free the buffer and restore `p' */
                     "free(p + 1);\n"
                     /*
@@ -572,7 +572,7 @@ encode_type (const char *name, const Type *t, const char *tmpstr)
                      *      \
                      *       +-- p
                      */
-                    "p = psave_%s - (1 + %lu - asn1_tag_length_%s); }\n",
+                    "p = psave_%s - (1 + %zu - asn1_tag_length_%s); }\n",
                     tmpstr, tmpstr, t->subtype->symbol->name,
                     tmpstr, t->subtype->symbol->name, t->subtype->symbol->name,
                     tmpstr, length_tag(t->tag.tagvalue),