diff --git a/lib/crypt-pbkdf1-sha1.c b/lib/crypt-pbkdf1-sha1.c
index 5e320d04..2727899e 100644
--- a/lib/crypt-pbkdf1-sha1.c
+++ b/lib/crypt-pbkdf1-sha1.c
@@ -155,6 +155,7 @@ crypt_sha1crypt_rn (const char *phrase, size_t phr_size,
    */
   dl = snprintf ((char *)output, out_size, "%.*s%s%lu",
                  (int)sl, setting, magic, iterations);
+  assert (dl > 0);
   /*
    * Then hmac using <phrase> as key, and repeat...
    */
@@ -165,8 +166,10 @@ crypt_sha1crypt_rn (const char *phrase, size_t phr_size,
       hmac_sha1_process_data (hmac_buf, SHA1_SIZE, pwu, pl, hmac_buf);
     }
   /* Now output... */
-  pl = (size_t)snprintf ((char *)output, out_size, "%s%lu$%.*s$",
-                         magic, iterations, (int)sl, setting);
+  dl = snprintf ((char *)output, out_size, "%s%lu$%.*s$",
+                 magic, iterations, (int)sl, setting);
+  assert (dl > 0);
+  pl = (size_t) dl;
   ep = output + pl;
 
   /* Every 3 bytes of hash gives 24 bits which is 4 base64 chars */
diff --git a/lib/crypt-sha256.c b/lib/crypt-sha256.c
index 6d21fa3c..9b32df52 100644
--- a/lib/crypt-sha256.c
+++ b/lib/crypt-sha256.c
@@ -261,6 +261,7 @@ crypt_sha256crypt_rn (const char *phrase, size_t phr_size,
       int n = snprintf (cp,
                         SHA256_HASH_LENGTH - (sizeof (sha256_salt_prefix) - 1),
                         "%s%zu$", sha256_rounds_prefix, rounds);
+      assert (n > 0);
       cp += n;
     }
 
diff --git a/lib/crypt-sha512.c b/lib/crypt-sha512.c
index 59ae9708..11aa0116 100644
--- a/lib/crypt-sha512.c
+++ b/lib/crypt-sha512.c
@@ -265,6 +265,7 @@ crypt_sha512crypt_rn (const char *phrase, size_t phr_size,
       int n = snprintf (cp,
                         SHA512_HASH_LENGTH - (sizeof (sha512_salt_prefix) - 1),
                         "%s%zu$", sha512_rounds_prefix, rounds);
+      assert (n > 0);
       cp += n;
     }
 
diff --git a/lib/crypt-sunmd5.c b/lib/crypt-sunmd5.c
index 9a871db5..26faccd7 100644
--- a/lib/crypt-sunmd5.c
+++ b/lib/crypt-sunmd5.c
@@ -300,8 +300,9 @@ gensalt_sunmd5_rn (unsigned long count,
 
   assert (count != 0);
 
-  size_t written = (size_t) snprintf ((char *)output, o_size,
-                                      "%s,rounds=%lu$", SUNMD5_PREFIX, count);
+  int written = snprintf ((char *)output, o_size,
+                          "%s,rounds=%lu$", SUNMD5_PREFIX, count);
+  assert (written > 0);
 
 
   write_itoa64_4(output + written + 0, rbytes[2], rbytes[3], rbytes[4]);
diff --git a/lib/util-gensalt-sha.c b/lib/util-gensalt-sha.c
index 4c6cf780..e7c141a5 100644
--- a/lib/util-gensalt-sha.c
+++ b/lib/util-gensalt-sha.c
@@ -60,8 +60,12 @@ gensalt_sha_rn (char tag, size_t maxsalt, unsigned long defcount,
       written = 3;
     }
   else
-    written = (size_t) snprintf ((char *)output, output_size,
-                                 "$%c$rounds=%lu$", tag, count);
+    {
+      int w = snprintf ((char *)output, output_size,
+                        "$%c$rounds=%lu$", tag, count);
+      assert (w > 0);
+      written = (size_t) w;
+    }
 
   /* The length calculation above should ensure that this is always true.  */
   assert (written + 5 < output_size);