diff --git a/src/pkg/runtime/freebsd/386/defs.h b/src/pkg/runtime/freebsd/386/defs.h
index 128be9cc9aa..ae12b201950 100644
--- a/src/pkg/runtime/freebsd/386/defs.h
+++ b/src/pkg/runtime/freebsd/386/defs.h
@@ -61,6 +61,9 @@ enum {
 	BUS_OBJERR = 0x3,
 	SEGV_MAPERR = 0x1,
 	SEGV_ACCERR = 0x2,
+	ITIMER_REAL = 0,
+	ITIMER_VIRTUAL = 0x1,
+	ITIMER_PROF = 0x2,
 };
 
 // Types
@@ -154,7 +157,9 @@ struct Mcontext {
 	int32 mc_ownedfp;
 	int32 mc_spare1[1];
 	int32 mc_fpstate[128];
-	int32 mc_spare2[8];
+	int32 mc_fsbase;
+	int32 mc_gsbase;
+	int32 mc_spare2[6];
 };
 
 typedef struct Ucontext Ucontext;
@@ -165,6 +170,18 @@ struct Ucontext {
 	StackT uc_stack;
 	int32 uc_flags;
 	int32 __spare__[4];
-	byte pad0[12];
+	byte pad_godefs_0[12];
+};
+
+typedef struct Timeval Timeval;
+struct Timeval {
+	int32 tv_sec;
+	int32 tv_usec;
+};
+
+typedef struct Itimerval Itimerval;
+struct Itimerval {
+	Timeval it_interval;
+	Timeval it_value;
 };
 #pragma pack off