diff --git a/tcc.c b/tcc.c
index 4f4eb623..c2bb0dd0 100644
--- a/tcc.c
+++ b/tcc.c
@@ -171,6 +171,8 @@ static const char version[] =
         " Darwin"
 #elif defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
         " FreeBSD"
+#elif defined(__OpenBSD__)
+        " OpenBSD"
 #else
         " Linux"
 #endif
diff --git a/tcc.h b/tcc.h
index 5fd27b97..7bfac8b9 100644
--- a/tcc.h
+++ b/tcc.h
@@ -45,6 +45,9 @@
 /* XXX: need to define this to use them in non ISOC99 context */
 extern float strtof (const char *__nptr, char **__endptr);
 extern long double strtold (const char *__nptr, char **__endptr);
+# if defined(__FreeBSD__) || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__)
+extern char **environ;
+# endif
 #endif
 
 #ifdef _WIN32
diff --git a/tccrun.c b/tccrun.c
index 17f1eebc..f453f3f3 100644
--- a/tccrun.c
+++ b/tccrun.c
@@ -648,6 +648,9 @@ static void rt_getcontext(ucontext_t *uc, rt_context *rc)
 # elif defined(__NetBSD__)
     rc->ip = uc->uc_mcontext.__gregs[_REG_RIP];
     rc->fp = uc->uc_mcontext.__gregs[_REG_RBP];
+# elif defined(__OpenBSD__)
+    rc->ip = uc->sc_rip;
+    rc->fp = uc->sc_rbp;
 # else
     rc->ip = uc->uc_mcontext.gregs[REG_RIP];
     rc->fp = uc->uc_mcontext.gregs[REG_RBP];