diff --git a/auto/headers b/auto/headers
index d41d95a75..542b757c1 100644
--- a/auto/headers
+++ b/auto/headers
@@ -7,4 +7,3 @@ ngx_include="inttypes.h";  . auto/include
 ngx_include="limits.h";    . auto/include
 ngx_include="sys/filio.h"; . auto/include
 ngx_include="crypt.h";     . auto/include
-ngx_include="malloc.h";    . auto/include
diff --git a/src/os/unix/ngx_posix_config.h b/src/os/unix/ngx_posix_config.h
index 37176e0d2..ae6f70f6a 100644
--- a/src/os/unix/ngx_posix_config.h
+++ b/src/os/unix/ngx_posix_config.h
@@ -70,7 +70,7 @@
 #include <limits.h>             /* IOV_MAX */
 #endif
 
-#if (NGX_HAVE_MALLOC_H)
+#ifdef __CYGWIN__
 #include <malloc.h>             /* memalign() */
 #endif