diff --git a/unix/uxplink.c b/unix/uxplink.c
index 02014316..e3e72a57 100644
--- a/unix/uxplink.c
+++ b/unix/uxplink.c
@@ -17,6 +17,7 @@
 
 #define PUTTY_DO_GLOBALS               /* actually _define_ globals */
 #include "putty.h"
+#include "ssh.h"
 #include "storage.h"
 #include "tree234.h"
 
diff --git a/unix/uxputty.c b/unix/uxputty.c
index 7449c3ab..7e2a6817 100644
--- a/unix/uxputty.c
+++ b/unix/uxputty.c
@@ -13,6 +13,7 @@
 #define MAY_REFER_TO_GTK_IN_HEADERS
 
 #include "putty.h"
+#include "ssh.h"
 #include "storage.h"
 
 #include "gtkcompat.h"
diff --git a/version.c b/version.c
index 59e9ca75..620879c3 100644
--- a/version.c
+++ b/version.c
@@ -8,6 +8,9 @@
  * to do here is to drop it into variables of the right names.
  */
 
+#include "putty.h"
+#include "ssh.h"
+
 #ifdef SOURCE_COMMIT
 #include "empty.h"
 #endif
diff --git a/windows/winnet.c b/windows/winnet.c
index 52e5c4a1..6ff0cebb 100644
--- a/windows/winnet.c
+++ b/windows/winnet.c
@@ -16,6 +16,7 @@
 #include "putty.h"
 #include "network.h"
 #include "tree234.h"
+#include "ssh.h"
 
 #include <ws2tcpip.h>