diff --git a/headers/private/kernel/arch/x86/descriptors.h b/headers/private/kernel/arch/x86/descriptors.h
index 20db3e053a..8615027a16 100644
--- a/headers/private/kernel/arch/x86/descriptors.h
+++ b/headers/private/kernel/arch/x86/descriptors.h
@@ -86,15 +86,24 @@ set_segment_descriptor(struct segment_descriptor *desc, addr_t base, uint32 limi
 {
 	set_segment_descriptor_base(desc, base);
 
-	desc->limit_00_15 = (addr_t)limit & 0x0ffff;	// limit is 20 bits long
-	desc->limit_19_16 = ((addr_t)limit >> 16) & 0xf;
+	// limit is 20 bits long
+	if (limit & 0xfff00000) {
+		desc->limit_00_15 = ((addr_t)limit >> 12) & 0x0ffff;
+		desc->limit_19_16 = ((addr_t)limit >> 28) & 0xf;
+		desc->granularity = 1;	// 4 KB granularity
+	} else {
+		desc->limit_00_15 = (addr_t)limit & 0x0ffff;
+		desc->limit_19_16 = ((addr_t)limit >> 16) & 0xf;
+		desc->granularity = 0;	// 1 byte granularity
+	}
+		limit >>= 12;
+
 
 	desc->type = type;
 	desc->desc_type = DT_CODE_DATA_SEGMENT;
 	desc->privilege_level = privilegeLevel;
 
 	desc->present = 1;
-	desc->granularity = 1;	// 4 GB size (in page size steps)
 	desc->available = 0;	// system available bit is currently not used
 	desc->d_b = 1;			// 32-bit code
 
diff --git a/src/kernel/boot/platform/bios_ia32/mmu.cpp b/src/kernel/boot/platform/bios_ia32/mmu.cpp
index 05a3654b5e..47cb8d1394 100644
--- a/src/kernel/boot/platform/bios_ia32/mmu.cpp
+++ b/src/kernel/boot/platform/bios_ia32/mmu.cpp
@@ -379,14 +379,14 @@ mmu_init_for_kernel(void)
 
 		// put standard segment descriptors in it
 		clear_segment_descriptor(&gdt[0]);
-		set_segment_descriptor(&gdt[1], 0, 0xfffff, DT_CODE_READABLE, DPL_KERNEL);
+		set_segment_descriptor(&gdt[1], 0, 0xffffffff, DT_CODE_READABLE, DPL_KERNEL);
 			// seg 0x08 - kernel 4GB code
-		set_segment_descriptor(&gdt[2], 0, 0xfffff, DT_DATA_WRITEABLE, DPL_KERNEL);
+		set_segment_descriptor(&gdt[2], 0, 0xffffffff, DT_DATA_WRITEABLE, DPL_KERNEL);
 			// seg 0x10 - kernel 4GB data
 
-		set_segment_descriptor(&gdt[3], 0, 0xfffff, DT_CODE_READABLE, DPL_USER);
+		set_segment_descriptor(&gdt[3], 0, 0xffffffff, DT_CODE_READABLE, DPL_USER);
 			// seg 0x1b - ring 3 user 4GB code
-		set_segment_descriptor(&gdt[4], 0, 0xfffff, DT_DATA_WRITEABLE, DPL_USER);
+		set_segment_descriptor(&gdt[4], 0, 0xffffffff, DT_DATA_WRITEABLE, DPL_USER);
 			// seg 0x23 - ring 3 user 4GB data
 
 		// gdt[5] and above will be filled later by the kernel