diff --git a/include/jemalloc/internal/jemalloc_internal_inlines_a.h b/include/jemalloc/internal/jemalloc_internal_inlines_a.h
index 8adc02a6..ddde9b4e 100644
--- a/include/jemalloc/internal/jemalloc_internal_inlines_a.h
+++ b/include/jemalloc/internal/jemalloc_internal_inlines_a.h
@@ -10,7 +10,9 @@
 JEMALLOC_ALWAYS_INLINE malloc_cpuid_t
 malloc_getcpu(void) {
 	assert(have_percpu_arena);
-#if defined(JEMALLOC_HAVE_SCHED_GETCPU)
+#if defined(_WIN32)
+	return GetCurrentProcessorNumber();
+#elif defined(JEMALLOC_HAVE_SCHED_GETCPU)
 	return (malloc_cpuid_t)sched_getcpu();
 #else
 	not_reached();
diff --git a/include/jemalloc/internal/jemalloc_preamble.h.in b/include/jemalloc/internal/jemalloc_preamble.h.in
index 857fa326..4bfdb32c 100644
--- a/include/jemalloc/internal/jemalloc_preamble.h.in
+++ b/include/jemalloc/internal/jemalloc_preamble.h.in
@@ -161,7 +161,7 @@ static const bool config_log =
     false
 #endif
     ;
-#ifdef JEMALLOC_HAVE_SCHED_GETCPU
+#if defined(_WIN32) || defined(JEMALLOC_HAVE_SCHED_GETCPU)
 /* Currently percpu_arena depends on sched_getcpu. */
 #define JEMALLOC_PERCPU_ARENA
 #endif