diff --git a/src/x86_64/ucontext_i.h b/src/x86_64/ucontext_i.h
index 10816d70..c1249bf6 100644
--- a/src/x86_64/ucontext_i.h
+++ b/src/x86_64/ucontext_i.h
@@ -45,38 +45,38 @@ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
 #define UC_SIGMASK		0x128
 #define FPREGS_OFFSET_MXCSR	0x18
 #elif defined __FreeBSD__
+#define	UC_SIGMASK		0x0
+#define UC_MCONTEXT_GREGS_RDI	0x18
+#define UC_MCONTEXT_GREGS_RSI	0x20
+#define UC_MCONTEXT_GREGS_RDX	0x28
+#define UC_MCONTEXT_GREGS_RCX	0x30
 #define UC_MCONTEXT_GREGS_R8	0x38
 #define UC_MCONTEXT_GREGS_R9	0x40
+#define UC_MCONTEXT_GREGS_RAX	0x48
+#define UC_MCONTEXT_GREGS_RBX	0x50
+#define UC_MCONTEXT_GREGS_RBP	0x58
 #define UC_MCONTEXT_GREGS_R10	0x60
 #define UC_MCONTEXT_GREGS_R11	0x68
 #define UC_MCONTEXT_GREGS_R12	0x70
 #define UC_MCONTEXT_GREGS_R13	0x78
 #define UC_MCONTEXT_GREGS_R14	0x80
 #define UC_MCONTEXT_GREGS_R15	0x88
-#define UC_MCONTEXT_GREGS_RDI	0x18
-#define UC_MCONTEXT_GREGS_RSI	0x20
-#define UC_MCONTEXT_GREGS_RBP	0x58
-#define UC_MCONTEXT_GREGS_RBX	0x50
-#define UC_MCONTEXT_GREGS_RDX	0x28
-#define UC_MCONTEXT_GREGS_RAX	0x48
-#define UC_MCONTEXT_GREGS_RCX	0x30
-#define UC_MCONTEXT_GREGS_RSP	0xc8
-#define UC_MCONTEXT_GREGS_RIP	0xb0
-#define UC_MCONTEXT_RFLAGS	0xc0
-#define UC_MCONTEXT_FLAGS	0xa0
-#define UC_MCONTEXT_CS		0xb8
-#define UC_MCONTEXT_SS		0xd0
-#define UC_MCONTEXT_DS		0xa6
-#define UC_MCONTEXT_ES		0xa4
 #define UC_MCONTEXT_FS		0x94
 #define UC_MCONTEXT_GS		0x96
+#define UC_MCONTEXT_FLAGS	0xa0
+#define UC_MCONTEXT_ES		0xa4
+#define UC_MCONTEXT_DS		0xa6
+#define UC_MCONTEXT_GREGS_RIP	0xb0
+#define UC_MCONTEXT_CS		0xb8
+#define UC_MCONTEXT_RFLAGS	0xc0
+#define UC_MCONTEXT_GREGS_RSP	0xc8
+#define UC_MCONTEXT_SS		0xd0
 #define UC_MCONTEXT_MC_LEN	0xd8
-#define UC_MCONTEXT_FPSTATE	0xf0
-#define UC_MCONTEXT_OWNEDFP	0xe8
 #define UC_MCONTEXT_FPFORMAT	0xe0
+#define UC_MCONTEXT_OWNEDFP	0xe8
+#define UC_MCONTEXT_FPSTATE	0xf0
 #define UC_MCONTEXT_FPOWNED_FPU	0x20001
 #define UC_MCONTEXT_FPFMT_XMM	0x10002
 #define UC_MCONTEXT_MC_LEN_VAL	0x320
-#define	UC_SIGMASK		0x0
 
 #endif