diff --git a/src/86box.c b/src/86box.c
index 8c07daa15..1c11d9bee 100644
--- a/src/86box.c
+++ b/src/86box.c
@@ -1656,6 +1656,10 @@ pc_close(UNUSED(thread_t *ptr))
     scsi_disk_close();
 
     gdbstub_close();
+
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
+    mem_free();
+#endif
 }
 
 #ifdef __APPLE__
diff --git a/src/include/86box/mem.h b/src/include/86box/mem.h
index 62cb493a5..53001b8db 100644
--- a/src/include/86box/mem.h
+++ b/src/include/86box/mem.h
@@ -265,12 +265,16 @@ extern uint32_t biosmask;
 extern uint32_t biosaddr;
 
 extern int        readlookup[256];
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 extern uintptr_t *readlookup2;
+#endif
 extern uintptr_t  old_rl2;
 extern uint8_t    uncached;
 extern int        readlnext;
 extern int        writelookup[256];
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 extern uintptr_t *writelookup2;
+#endif
 extern int        writelnext;
 extern uint32_t   ram_mapped_addr[64];
 extern uint8_t    page_ff[4096];
@@ -288,7 +292,16 @@ extern mem_mapping_t bios_high_mapping;
 extern uint32_t mem_logical_addr;
 
 extern page_t  *pages;
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 extern page_t **page_lookup;
+#endif
+
+#if (defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64)
+/* The lookup tables. */
+extern page_t *page_lookup[1048576];
+extern uintptr_t readlookup2[1048576];
+extern uintptr_t writelookup2[1048576];
+#endif
 
 extern uint32_t get_phys_virt;
 extern uint32_t get_phys_phys;
@@ -457,6 +470,9 @@ extern void mem_a20_init(void);
 extern void mem_a20_recalc(void);
 
 extern void mem_init(void);
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
+extern void mem_free(void);
+#endif
 extern void mem_close(void);
 extern void mem_zero(void);
 extern void mem_reset(void);
diff --git a/src/mem/mem.c b/src/mem/mem.c
index d365ecffb..fa749002c 100644
--- a/src/mem/mem.c
+++ b/src/mem/mem.c
@@ -67,7 +67,9 @@ mem_mapping_t bios_mapping;
 mem_mapping_t bios_high_mapping;
 
 page_t  *pages;       /* RAM page table */
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 page_t **page_lookup; /* pagetable lookup */
+#endif
 uint32_t pages_sz;    /* #pages in table */
 
 uint8_t *ram;  /* the virtual RAM */
@@ -85,12 +87,23 @@ uint8_t *pccache2;
 
 int        readlnext;
 int        readlookup[256];
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 uintptr_t *readlookup2;
+#endif
 uintptr_t  old_rl2;
 uint8_t    uncached = 0;
 int        writelnext;
 int        writelookup[256];
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
 uintptr_t *writelookup2;
+#endif
+
+#if (defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64)
+/* The lookup tables. */
+page_t *page_lookup[1048576] = { 0 };
+uintptr_t readlookup2[1048576] = { 0 };
+uintptr_t writelookup2[1048576] = { 0 };
+#endif
 
 uint32_t mem_logical_addr;
 
@@ -2987,12 +3000,25 @@ mem_init(void)
     ram2      = NULL;
     pages     = NULL;
 
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
     /* Allocate the lookup tables. */
     page_lookup  = (page_t **) malloc((1 << 20) * sizeof(page_t *));
     readlookup2  = malloc((1 << 20) * sizeof(uintptr_t));
     writelookup2 = malloc((1 << 20) * sizeof(uintptr_t));
+#endif
 }
 
+#if (!(defined __amd64__ || defined _M_X64 || defined __aarch64__ || defined _M_ARM64))
+void
+mem_free(void)
+{
+    free(page_lookup);
+    free(readlookup2);
+    free(writelookup2);
+}
+#endif
+
+
 static void
 umc_page_recalc(uint32_t c, uint32_t phys, int set)
 {