diff --git a/src/crypto/crypto-ops.c b/src/crypto/crypto-ops.c
index 314fe448a..1d8852e14 100644
--- a/src/crypto/crypto-ops.c
+++ b/src/crypto/crypto-ops.c
@@ -2429,6 +2429,14 @@ void sc_0(unsigned char *s) {
   }
 }
 
+void sc_1(unsigned char *s) {
+  int i;
+  s[0] = 1;
+  for (i = 1; i < 32; i++) {
+    s[i] = 0;
+  }
+}
+
 void sc_reduce32(unsigned char *s) {
   int64_t s0 = 2097151 & load_3(s);
   int64_t s1 = 2097151 & (load_4(s + 2) >> 5);
diff --git a/src/crypto/crypto-ops.h b/src/crypto/crypto-ops.h
index c103f1f78..dcb335d2d 100644
--- a/src/crypto/crypto-ops.h
+++ b/src/crypto/crypto-ops.h
@@ -147,6 +147,7 @@ extern const ge_p3 ge_p3_identity;
 extern const ge_p3 ge_p3_H;
 void ge_fromfe_frombytes_vartime(ge_p2 *, const unsigned char *);
 void sc_0(unsigned char *);
+void sc_1(unsigned char *);
 void sc_reduce32(unsigned char *);
 void sc_add(unsigned char *, const unsigned char *, const unsigned char *);
 void sc_sub(unsigned char *, const unsigned char *, const unsigned char *);