diff --git a/ssh.c b/ssh.c
index 6e55107d..7031a554 100644
--- a/ssh.c
+++ b/ssh.c
@@ -47,23 +47,6 @@ static const char *const ssh2_disconnect_reasons[] = {
     "illegal user name",
 };
 
-/*
- * Various remote-bug flags.
- */
-#define BUG_CHOKES_ON_SSH1_IGNORE                 1
-#define BUG_SSH2_HMAC                             2
-#define BUG_NEEDS_SSH1_PLAIN_PASSWORD        	  4
-#define BUG_CHOKES_ON_RSA	        	  8
-#define BUG_SSH2_RSA_PADDING	        	 16
-#define BUG_SSH2_DERIVEKEY                       32
-#define BUG_SSH2_REKEY                           64
-#define BUG_SSH2_PK_SESSIONID                   128
-#define BUG_SSH2_MAXPKT				256
-#define BUG_CHOKES_ON_SSH2_IGNORE               512
-#define BUG_CHOKES_ON_WINADJ                   1024
-#define BUG_SENDS_LATE_REQUEST_REPLY           2048
-#define BUG_SSH2_OLDGEX                        4096
-
 #define DH_MIN_SIZE 1024
 #define DH_MAX_SIZE 8192
 
diff --git a/ssh.h b/ssh.h
index 8a411710..7dbd31fe 100644
--- a/ssh.h
+++ b/ssh.h
@@ -1266,3 +1266,29 @@ const char *ssh2_pkt_type(Pkt_KCtx pkt_kctx, Pkt_ACtx pkt_actx, int type);
  * format.
  */
 void old_keyfile_warning(void);
+
+/*
+ * Flags indicating implementation bugs that we know how to mitigate
+ * if we think the other end has them.
+ */
+#define SSH_IMPL_BUG_LIST(X)                    \
+    X(BUG_CHOKES_ON_SSH1_IGNORE)                \
+    X(BUG_SSH2_HMAC)                            \
+    X(BUG_NEEDS_SSH1_PLAIN_PASSWORD)            \
+    X(BUG_CHOKES_ON_RSA)                        \
+    X(BUG_SSH2_RSA_PADDING)                     \
+    X(BUG_SSH2_DERIVEKEY)                       \
+    X(BUG_SSH2_REKEY)                           \
+    X(BUG_SSH2_PK_SESSIONID)                    \
+    X(BUG_SSH2_MAXPKT)                          \
+    X(BUG_CHOKES_ON_SSH2_IGNORE)                \
+    X(BUG_CHOKES_ON_WINADJ)                     \
+    X(BUG_SENDS_LATE_REQUEST_REPLY)             \
+    X(BUG_SSH2_OLDGEX)                          \
+    /* end of list */
+#define TMP_DECLARE_LOG2_ENUM(thing) log2_##thing,
+enum { SSH_IMPL_BUG_LIST(TMP_DECLARE_LOG2_ENUM) };
+#undef TMP_DECLARE_LOG2_ENUM
+#define TMP_DECLARE_REAL_ENUM(thing) thing = 1 << log2_##thing,
+enum { SSH_IMPL_BUG_LIST(TMP_DECLARE_REAL_ENUM) };
+#undef TMP_DECLARE_REAL_ENUM