diff --git a/lib/md5.c b/lib/md5.c
index 7df66f524a..774d6b02a3 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -153,6 +153,7 @@ static void MD5_Final(unsigned char digest[16], MD5_CTX *ctx)
 }
 
 #elif defined(USE_AXTLS)
+#include <axTLS/config.h>
 #include <axTLS/os_int.h>
 #include <axTLS/crypto.h>
 #else
diff --git a/lib/urldata.h b/lib/urldata.h
index 202d81951b..caa5debf10 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -120,6 +120,7 @@
 #endif
 
 #ifdef USE_AXTLS
+#include <axTLS/config.h>
 #include <axTLS/ssl.h>
 #undef malloc
 #undef calloc
diff --git a/lib/vtls/axtls.c b/lib/vtls/axtls.c
index 4907d20751..930136a232 100644
--- a/lib/vtls/axtls.c
+++ b/lib/vtls/axtls.c
@@ -29,6 +29,7 @@
 #include "curl_setup.h"
 
 #ifdef USE_AXTLS
+#include <axTLS/config.h>
 #include <axTLS/ssl.h>
 #include "axtls.h"