diff --git a/cmdgen.c b/cmdgen.c
index 94ce49ea..265e5adc 100644
--- a/cmdgen.c
+++ b/cmdgen.c
@@ -223,6 +223,8 @@ static char *readpassphrase(const char *filename)
     return line;
 }
 
+#define DEFAULT_RSADSA_BITS 2048
+
 int main(int argc, char **argv)
 {
     char *infile = NULL;
@@ -500,7 +502,7 @@ int main(int argc, char **argv)
             bits = 256;
             break;
           default:
-            bits = 2048;
+            bits = DEFAULT_RSADSA_BITS;
             break;
         }
     }
@@ -520,6 +522,11 @@ int main(int argc, char **argv)
             fprintf(stderr, "puttygen: cannot generate %s keys shorter than"
                     " 256 bits\n", (keytype == DSA ? "DSA" : "RSA"));
             errs = TRUE;
+        } else if (bits < DEFAULT_RSADSA_BITS) {
+            fprintf(stderr, "puttygen: warning: %s keys shorter than"
+                    " %d bits are probably not secure\n",
+                    (keytype == DSA ? "DSA" : "RSA"), DEFAULT_RSADSA_BITS);
+            /* but this is just a warning, so proceed anyway */
         }
     }
 
diff --git a/windows/winpgen.c b/windows/winpgen.c
index c4f3d57f..277c0914 100644
--- a/windows/winpgen.c
+++ b/windows/winpgen.c
@@ -1115,6 +1115,7 @@ static INT_PTR CALLBACK MainDlgProc(HWND hwnd, UINT msg,
                 } else if (IsDlgButtonChecked(hwnd, IDC_KEYSSH2ED25519)) {
                     state->keytype = ED25519;
                 }
+
 		if ((state->keytype == RSA || state->keytype == DSA) &&
                     state->key_bits < 256) {
                     char *message = dupprintf
@@ -1128,7 +1129,18 @@ static INT_PTR CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 			break;
 		    state->key_bits = DEFAULT_KEY_BITS;
 		    SetDlgItemInt(hwnd, IDC_BITS, DEFAULT_KEY_BITS, FALSE);
-		}
+		} else if ((state->keytype == RSA || state->keytype == DSA) &&
+                           state->key_bits < DEFAULT_KEY_BITS) {
+                    char *message = dupprintf
+                        ("Keys shorter than %d bits are not recommended. "
+                         "Really generate this key?", DEFAULT_KEY_BITS);
+		    int ret = MessageBox(hwnd, message, "PuTTYgen Warning",
+					 MB_ICONWARNING | MB_OKCANCEL);
+                    sfree(message);
+		    if (ret != IDOK)
+			break;
+                }
+
 		ui_set_state(hwnd, state, 1);
 		SetDlgItemText(hwnd, IDC_GENERATING, entropy_msg);
 		state->key_exists = FALSE;