diff --git a/iseq.c b/iseq.c
index 19fd8fcb18..19ac0e0d43 100644
--- a/iseq.c
+++ b/iseq.c
@@ -42,7 +42,6 @@
 #include "builtin.h"
 #include "insns.inc"
 #include "insns_info.inc"
-#include <sys/mman.h>
 
 VALUE rb_cISeq;
 static VALUE iseqw_new(const rb_iseq_t *iseq);
diff --git a/ujit_asm.c b/ujit_asm.c
index 8efbee3f79..e8aee15fab 100644
--- a/ujit_asm.c
+++ b/ujit_asm.c
@@ -3,8 +3,10 @@
 #include <stdarg.h>
 #include <assert.h>
 
+#ifndef _WIN32
 // For mmapp()
 #include <sys/mman.h>
+#endif
 
 #include "ujit_asm.h"
 
@@ -82,6 +84,7 @@ x86opnd_t const_ptr_opnd(void* ptr)
 // Allocate a block of executable memory
 uint8_t* alloc_exec_mem(size_t mem_size)
 {
+#ifndef _WIN32
     // Map the memory as executable
     uint8_t* mem_block = (uint8_t*)mmap(
         &alloc_exec_mem,
@@ -100,6 +103,9 @@ uint8_t* alloc_exec_mem(size_t mem_size)
     }
 
     return mem_block;
+#else
+    return NULL;
+#endif
 }
 
 // Initialize a code block object
diff --git a/ujit_compile.c b/ujit_compile.c
index cee9e383e7..6740a80765 100644
--- a/ujit_compile.c
+++ b/ujit_compile.c
@@ -13,6 +13,12 @@
 // eg ujit_hook.h
 #include "ujit_examples.inc"
 
+#ifdef _WIN32
+#define PLATFORM_SUPPORTED_P 0
+#else
+#define PLATFORM_SUPPORTED_P 1
+#endif
+
 // Hash table of encoded instructions
 extern st_table *rb_encoded_insn_data;
 
@@ -505,7 +511,7 @@ rb_ujit_enabled_p(void)
 void
 rb_ujit_init(void)
 {
-    if (!ujit_scrape_successful) {
+    if (!ujit_scrape_successful && PLATFORM_SUPPORTED_P) {
         return;
     }
     // Initialize the code blocks