diff --git a/OpenCL/m13800_a0.cl b/OpenCL/m13800_a0.cl
index 7aa322862..38be7adbe 100644
--- a/OpenCL/m13800_a0.cl
+++ b/OpenCL/m13800_a0.cl
@@ -37,7 +37,7 @@ __constant u32 k_sha256[64] =
   SHA256C3c, SHA256C3d, SHA256C3e, SHA256C3f,
 };
 
-void sha256_transform (const u32x w[16], u32x digest[8])
+static void sha256_transform (const u32x w[16], u32x digest[8])
 {
   u32x a = digest[0];
   u32x b = digest[1];
@@ -125,7 +125,7 @@ void sha256_transform (const u32x w[16], u32x digest[8])
   digest[7] += h;
 }
 
-void memcat64c_be (u32x block[16], const u32 offset, u32x carry[16])
+static void memcat64c_be (u32x block[16], const u32 offset, u32x carry[16])
 {
   const u32 mod = offset & 3;
   const u32 div = offset / 4;