diff --git a/import/OpenXDK/include/xboxkrnl/kernel.h b/import/OpenXDK/include/xboxkrnl/kernel.h
index cc1624385..93a8f7e70 100644
--- a/import/OpenXDK/include/xboxkrnl/kernel.h
+++ b/import/OpenXDK/include/xboxkrnl/kernel.h
@@ -321,7 +321,7 @@ XBSYSAPI EXPORTNUM(132) LONG NTAPI KeReleaseSemaphore
 (
 	IN PRKSEMAPHORE Semaphore,
 	IN KPRIORITY Increment,
-	IN BOOLEAN Adjustment,
+	IN LONG Adjustment,
 	IN BOOLEAN Wait
 );
 
diff --git a/import/OpenXDK/include/xboxkrnl/xboxkrnl.h b/import/OpenXDK/include/xboxkrnl/xboxkrnl.h
index da9c774eb..5f1af9889 100644
--- a/import/OpenXDK/include/xboxkrnl/xboxkrnl.h
+++ b/import/OpenXDK/include/xboxkrnl/xboxkrnl.h
@@ -152,6 +152,7 @@ typedef long                            NTSTATUS;
 #define STATUS_USER_APC                  ((DWORD   )0x000000C0L)
 // The SCSI input buffer was too large (not necessarily an error!)
 #define STATUS_DATA_OVERRUN              ((DWORD   )0xC000003CL)
+#define STATUS_SEMAPHORE_LIMIT_EXCEEDED  ((DWORD   )0xC0000047L)
 #define STATUS_INVALID_IMAGE_FORMAT      ((DWORD   )0xC000007BL)
 #define STATUS_INSUFFICIENT_RESOURCES    ((DWORD   )0xC000009AL)
 #define STATUS_TOO_MANY_SECRETS          ((DWORD   )0xC0000156L)
diff --git a/src/core/kernel/exports/EmuKrnlEx.cpp b/src/core/kernel/exports/EmuKrnlEx.cpp
index 6f1185a99..5f185ed5a 100644
--- a/src/core/kernel/exports/EmuKrnlEx.cpp
+++ b/src/core/kernel/exports/EmuKrnlEx.cpp
@@ -600,11 +600,11 @@ XBSYSAPI EXPORTNUM(28) xboxkrnl::VOID NTAPI xboxkrnl::ExReleaseReadWriteLock
 
 	if (ReadWriteLock->ReadersEntryCount == 0) {
 		if (ReadWriteLock->ReadersWaitingCount != 0) {
-			ULONG temp_readers_waiting = ReadWriteLock->ReadersWaitingCount;
+			ULONG orig_readers_waiting = ReadWriteLock->ReadersWaitingCount;
 			ReadWriteLock->ReadersEntryCount = ReadWriteLock->ReadersWaitingCount;
 			ReadWriteLock->ReadersWaitingCount = 0;
 			RestoreInterruptMode(interrupt_mode);
-			KeReleaseSemaphore(&ReadWriteLock->ReaderSemaphore, 1, (BOOLEAN)temp_readers_waiting, 0);
+			KeReleaseSemaphore(&ReadWriteLock->ReaderSemaphore, 1, (LONG)orig_readers_waiting, 0);
 			return;
 		}
 	}
diff --git a/src/core/kernel/exports/EmuKrnlKe.cpp b/src/core/kernel/exports/EmuKrnlKe.cpp
index 2327e471f..3aa40f51c 100644
--- a/src/core/kernel/exports/EmuKrnlKe.cpp
+++ b/src/core/kernel/exports/EmuKrnlKe.cpp
@@ -1314,7 +1314,7 @@ XBSYSAPI EXPORTNUM(132) xboxkrnl::LONG NTAPI xboxkrnl::KeReleaseSemaphore
 (
 	IN PRKSEMAPHORE Semaphore,
 	IN KPRIORITY Increment,
-	IN BOOLEAN Adjustment,
+	IN LONG Adjustment,
 	IN BOOLEAN Wait
 )
 {
@@ -1325,9 +1325,35 @@ XBSYSAPI EXPORTNUM(132) xboxkrnl::LONG NTAPI xboxkrnl::KeReleaseSemaphore
 		LOG_FUNC_ARG(Wait)
 		LOG_FUNC_END;
 
-	LOG_UNIMPLEMENTED();
+	UCHAR orig_irql = KeRaiseIrqlToDpcLevel();
+	LONG initial_state = Semaphore->Header.SignalState;
+	LONG adjusted_signalstate = Semaphore->Header.SignalState + Adjustment;
+
+	BOOL limit_reached = adjusted_signalstate > Semaphore->Limit;
+	BOOL signalstate_overflow = adjusted_signalstate < initial_state;
+	if (limit_reached || signalstate_overflow) {
+		KiUnlockDispatcherDatabase(orig_irql);
+		ExRaiseStatus(STATUS_SEMAPHORE_LIMIT_EXCEEDED);
+	}
+	Semaphore->Header.SignalState = adjusted_signalstate;
+
+	//TODO: Implement KiWaitTest
+#if 0
+	if ((initial_state == 0) && (IsListEmpty(&Semaphore->Header.WaitListHead) == FALSE)) {
+		KiWaitTest(&Semaphore->Header, Increment);
+	}
+#endif
+
+	if (Wait) {
+		PKTHREAD current_thread = KeGetCurrentThread();
+		current_thread->WaitNext = TRUE;
+		current_thread->WaitIrql = orig_irql;
+	}
+	else {
+		KiUnlockDispatcherDatabase(orig_irql);
+	}
 
-	RETURN(0);
+	RETURN(initial_state);
 }
 
 XBSYSAPI EXPORTNUM(133) xboxkrnl::PKDEVICE_QUEUE_ENTRY NTAPI xboxkrnl::KeRemoveByKeyDeviceQueue