diff --git a/g10/keygen.c b/g10/keygen.c
index af54c3f02..54d37d01b 100644
--- a/g10/keygen.c
+++ b/g10/keygen.c
@@ -1378,11 +1378,16 @@ gen_elg (int algo, unsigned int nbits, KBNODE pub_root,
 
   assert (is_ELGAMAL (algo));
 
-  if (nbits < 512)
+  if (nbits < 1024)
     {
       nbits = 2048;
       log_info (_("keysize invalid; using %u bits\n"), nbits );
     }
+  else if (nbits > 4096)
+    {
+      nbits = 4096;
+      log_info (_("keysize invalid; using %u bits\n"), nbits );
+    }
 
   if ((nbits % 32))
     {
@@ -1428,7 +1433,7 @@ gen_dsa (unsigned int nbits, KBNODE pub_root,
   char nbitsstr[35];
   char qbitsstr[35];
 
-  if ( nbits < 512)
+  if (nbits < 768)
     {
       nbits = 2048;
       log_info(_("keysize invalid; using %u bits\n"), nbits );
@@ -1562,6 +1567,11 @@ gen_rsa (int algo, unsigned int nbits, KBNODE pub_root,
       nbits = 2048;
       log_info (_("keysize invalid; using %u bits\n"), nbits );
     }
+  else if (nbits > 4096)
+    {
+      nbits = 4096;
+      log_info (_("keysize invalid; using %u bits\n"), nbits );
+    }
 
   if ((nbits % 32))
     {