diff --git a/crypto/fipsmodule/modes/internal.h b/crypto/fipsmodule/modes/internal.h
index 38cc70e..23aaca2 100644
--- a/crypto/fipsmodule/modes/internal.h
+++ b/crypto/fipsmodule/modes/internal.h
@@ -50,6 +50,7 @@
 #define OPENSSL_HEADER_MODES_INTERNAL_H
 
 #include <openssl/base.h>
+#include <openssl/aes.h>
 
 #include <string.h>