diff --git a/kernel/bootstrap.c b/kernel/bootstrap.c
index 3f26d96..7592c83 100644
--- a/kernel/bootstrap.c
+++ b/kernel/bootstrap.c
@@ -780,7 +780,7 @@ void InstallGDT() {
     uint16_t TSSBase1 = (uint16_t)TSS64Address;
     uint8_t TSSBase2 = (uint8_t)(TSS64Address >> 16);
     uint8_t TSSBase3 = (uint8_t)(TSS64Address >> 24);
-    uint32_t TSSBase4 = (uint8_t)(TSS64Address >> 32);
+    uint32_t TSSBase4 = (uint32_t)(TSS64Address >> 32);
 
     GDTData.Limit = sizeof(InitialGDT) - 1;
     GDTData.BaseAddress = (size_t)InitialGDT;