diff --git a/arch/x86/include/asm/kaiser.h b/arch/x86/include/asm/kaiser.h
index 802bbbdfe143..48c791a411ab 100644
--- a/arch/x86/include/asm/kaiser.h
+++ b/arch/x86/include/asm/kaiser.h
@@ -19,6 +19,16 @@
 
 #define KAISER_SHADOW_PGD_OFFSET 0x1000
 
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+/*
+ *  A page table address must have this alignment to stay the same when
+ *  KAISER_SHADOW_PGD_OFFSET mask is applied
+ */
+#define KAISER_KERNEL_PGD_ALIGNMENT (KAISER_SHADOW_PGD_OFFSET << 1)
+#else
+#define KAISER_KERNEL_PGD_ALIGNMENT PAGE_SIZE
+#endif
+
 #ifdef __ASSEMBLY__
 #ifdef CONFIG_PAGE_TABLE_ISOLATION
 
diff --git a/arch/x86/realmode/init.c b/arch/x86/realmode/init.c
index 0b7a63d98440..805a3271a137 100644
--- a/arch/x86/realmode/init.c
+++ b/arch/x86/realmode/init.c
@@ -4,6 +4,7 @@
 #include <asm/cacheflush.h>
 #include <asm/pgtable.h>
 #include <asm/realmode.h>
+#include <asm/kaiser.h>
 
 struct real_mode_header *real_mode_header;
 u32 *trampoline_cr4_features;
@@ -15,7 +16,8 @@ void __init reserve_real_mode(void)
 	size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
 
 	/* Has to be under 1M so we can execute real-mode AP code. */
-	mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
+	mem = memblock_find_in_range(0, 1 << 20, size,
+				     KAISER_KERNEL_PGD_ALIGNMENT);
 	if (!mem)
 		panic("Cannot allocate trampoline\n");
 
diff --git a/arch/x86/realmode/rm/trampoline_64.S b/arch/x86/realmode/rm/trampoline_64.S
index dac7b20d2f9d..781cca63f795 100644
--- a/arch/x86/realmode/rm/trampoline_64.S
+++ b/arch/x86/realmode/rm/trampoline_64.S
@@ -30,6 +30,7 @@
 #include <asm/msr.h>
 #include <asm/segment.h>
 #include <asm/processor-flags.h>
+#include <asm/kaiser.h>
 #include "realmode.h"
 
 	.text
@@ -139,7 +140,7 @@ tr_gdt:
 tr_gdt_end:
 
 	.bss
-	.balign	PAGE_SIZE
+	.balign	KAISER_KERNEL_PGD_ALIGNMENT
 GLOBAL(trampoline_pgd)		.space	PAGE_SIZE
 
 	.balign	8