diff --git a/android/jni/ed25519/additions/curve_sigs.c b/android/jni/ed25519/additions/curve_sigs.c
index f6026fe..7a49b18 100644
--- a/android/jni/ed25519/additions/curve_sigs.c
+++ b/android/jni/ed25519/additions/curve_sigs.c
@@ -1,4 +1,5 @@
 #include <string.h>
+#include <stdlib.h>
 #include "ge.h"
 #include "curve_sigs.h"
 #include "crypto_sign.h"