diff --git a/src/core/sys/freebsd/config.d b/src/core/sys/freebsd/config.d
index cc6ff84abf2..4eda066b293 100644
--- a/src/core/sys/freebsd/config.d
+++ b/src/core/sys/freebsd/config.d
@@ -11,6 +11,8 @@ public import core.sys.posix.config;
 
 // https://svnweb.freebsd.org/base/head/sys/sys/param.h?view=markup
 // __FreeBSD_version numbers are documented in the Porter's Handbook.
+// NOTE: When adding newer versions of FreeBSD, verify all current versioned
+// bindings are still compatible with the release.
      version (FreeBSD_12) enum __FreeBSD_version = 1202000;
 else version (FreeBSD_11) enum __FreeBSD_version = 1104000;
 else version (FreeBSD_10) enum __FreeBSD_version = 1004000;
diff --git a/src/core/sys/freebsd/sys/event.d b/src/core/sys/freebsd/sys/event.d
index cc1c25a8b05..2bd3839f095 100644
--- a/src/core/sys/freebsd/sys/event.d
+++ b/src/core/sys/freebsd/sys/event.d
@@ -39,7 +39,7 @@ enum
     EVFILT_SYSCOUNT =  11,
 }
 
-static if (__FreeBSD_version >= 1200000 && __FreeBSD_version < 1300000)
+static if (__FreeBSD_version >= 1200000)
 {
     struct kevent_t
     {
@@ -52,7 +52,7 @@ static if (__FreeBSD_version >= 1200000 && __FreeBSD_version < 1300000)
         ulong[4]  ext;
     }
 }
-else static if (__FreeBSD_version < 1200000)
+else
 {
     struct kevent_t
     {
@@ -64,8 +64,6 @@ else static if (__FreeBSD_version < 1200000)
         void        *udata; /* opaque user data identifier */
     }
 }
-else
-    static assert(0, "Unsupported version of FreeBSD");
 
 extern(D) void EV_SET(kevent_t* kevp, typeof(kevent_t.tupleof) args)
 {
diff --git a/src/core/sys/freebsd/sys/mount.d b/src/core/sys/freebsd/sys/mount.d
index 42725750acc..7051dd675c5 100644
--- a/src/core/sys/freebsd/sys/mount.d
+++ b/src/core/sys/freebsd/sys/mount.d
@@ -34,18 +34,16 @@ struct fid
 
 enum MFSNAMELEN = 16;
 
-static if (__FreeBSD_version >= 1200000 && __FreeBSD_version < 1300000)
+static if (__FreeBSD_version >= 1200000)
 {
     enum MNAMELEN   = 1024;
     enum STATFS_VERSION = 0x20140518;
 }
-else static if (__FreeBSD_version < 1200000)
+else
 {
     enum MNAMELEN   = 88;
     enum STATFS_VERSION = 0x20030518;
 }
-else
-    static assert(0, "Unsupported version of FreeBSD");
 
 struct statfs_t
 {
diff --git a/src/core/sys/posix/dirent.d b/src/core/sys/posix/dirent.d
index 1133162e7f1..61826d5cd46 100644
--- a/src/core/sys/posix/dirent.d
+++ b/src/core/sys/posix/dirent.d
@@ -157,7 +157,7 @@ else version (FreeBSD)
         DT_WHT      = 14
     }
 
-    static if (__FreeBSD_version >= 1200000 && __FreeBSD_version < 1300000)
+    static if (__FreeBSD_version >= 1200000)
     {
         struct dirent
         {
@@ -170,7 +170,7 @@ else version (FreeBSD)
             char[256] d_name = 0;
         }
     }
-    else static if (__FreeBSD_version < 1200000)
+    else
     {
         align(4)
         struct dirent
@@ -182,8 +182,6 @@ else version (FreeBSD)
             char[256] d_name = 0;
         }
     }
-    else
-        static assert(0, "Unsupported version of FreeBSD");
 
     alias void* DIR;
 
diff --git a/src/core/sys/posix/sys/types.d b/src/core/sys/posix/sys/types.d
index ad525b73540..6195c03d751 100644
--- a/src/core/sys/posix/sys/types.d
+++ b/src/core/sys/posix/sys/types.d
@@ -197,22 +197,20 @@ else version (FreeBSD)
     // https://github.com/freebsd/freebsd/blob/master/sys/sys/_types.h
     alias long      blkcnt_t;
 
-    static if (__FreeBSD_version >= 1200000 && __FreeBSD_version < 1300000)
+    static if (__FreeBSD_version >= 1200000)
     {
         alias ulong blksize_t;
         alias ulong dev_t;
         alias ulong ino_t;
         alias ulong nlink_t;
     }
-    else static if (__FreeBSD_version < 1200000)
+    else
     {
         alias uint   blksize_t;
         alias uint   dev_t;
         alias uint   ino_t;
         alias ushort nlink_t;
     }
-    else
-        static assert(0, "Unsupported version of FreeBSD");
 
     alias uint      gid_t;
     alias ushort    mode_t;