diff --git a/Makefile b/Makefile
index f7076323..9e60da56 100644
--- a/Makefile
+++ b/Makefile
@@ -198,7 +198,7 @@ COMMON_DEFINES  := -D_MIPS_SZLONG=32
 GBI_DEFINES     := -DF3DEX_GBI
 RELEASE_DEFINES := -DNDEBUG -D_FINALROM
 AS_DEFINES      := -DMIPSEB -D_LANGUAGE_ASSEMBLY -D_ULTRA64
-C_DEFINES       := -DLANGUAGE_C -D_LANGUAGE_C
+C_DEFINES       := -DLANGUAGE_C -D_LANGUAGE_C -DBUILD_VERSION=VERSION_H
 ENDIAN          := -EB
 
 OPTFLAGS        := -O2 -g3
@@ -274,6 +274,7 @@ build/src/libultra/libc/ll.o: OPTFLAGS := -O1 -g0
 build/src/libultra/libc/ll.o: MIPS_VERSION := -mips3 -32
 
 build/src/libultra/os/createmesgqueue.o: OPTFLAGS := -O1 -g0
+build/src/libultra/os/destroythread.o: OPTFLAGS := -O1 -g0
 build/src/libultra/os/getactivequeue.o: OPTFLAGS := -O1 -g0
 build/src/libultra/os/stopthread.o: OPTFLAGS := -O1 -g0
 
diff --git a/src/libultra/os/destroythread.c b/src/libultra/os/destroythread.c
index 9fa2e0ee..a0d48d3b 100644
--- a/src/libultra/os/destroythread.c
+++ b/src/libultra/os/destroythread.c
@@ -1,3 +1,55 @@
-#include "common.h"
+#include "PR/os_internal.h"
+#include "osint.h"
+#include "PR/os_version.h"
 
-#pragma GLOBAL_ASM("asm/us/nonmatchings/libultra/os/destroythread/osDestroyThread.s")
+// this is not supposed to be here, but the def check below is broken I guess.
+#ifdef __sgi
+#define __GNUC__ 0
+#endif
+
+void osDestroyThread(OSThread* t) {
+    register u32 saveMask;
+    register OSThread* pred;
+    register OSThread* succ;
+
+    saveMask = __osDisableInt();
+
+    if (t == NULL) {
+        t = __osRunningThread;
+    } else if (t->state != OS_STATE_STOPPED) {
+        __osDequeueThread(t->queue, t);
+    }
+
+    if (__osActiveQueue == t) {
+        __osActiveQueue = __osActiveQueue->tlnext;
+    } else {
+#if BUILD_VERSION >= VERSION_J || !defined(__GNUC__)
+        pred = __osActiveQueue;
+        while (pred->priority != -1) {
+            succ = pred->tlnext;
+            if (succ == t) {
+                pred->tlnext = t->tlnext;
+                break;
+            }
+            pred = succ;
+        }
+#else
+        pred = __osActiveQueue;
+        succ = pred->tlnext;
+        while (succ != NULL) {
+            if (succ == t) {
+                pred->tlnext = t->tlnext;
+                break;
+            }
+            pred = succ;
+            succ = pred->tlnext;
+        }
+#endif
+    }
+
+    if (t == __osRunningThread) {
+        __osDispatchThread();
+    }
+
+    __osRestoreInt(saveMask);
+}