diff --git a/OpenCL/m07800_a3.cl b/OpenCL/m07800_a3.cl
index ad5144a61..77bd2d8b4 100644
--- a/OpenCL/m07800_a3.cl
+++ b/OpenCL/m07800_a3.cl
@@ -351,7 +351,7 @@ static void m07800m (u32 w0[4], u32 w1[4], u32 w2[4], u32 w3[4], const u32 pw_le
 
     u32 final_len = pw_len;
 
-    int i;
+    u32 i;
 
     // append MagicArray
 
@@ -582,7 +582,7 @@ static void m07800s (u32 w0[4], u32 w1[4], u32 w2[4], u32 w3[4], const u32 pw_le
 
     u32 final_len = pw_len;
 
-    int i;
+    u32 i;
 
     // append MagicArray
 
diff --git a/OpenCL/m10100_a3.cl b/OpenCL/m10100_a3.cl
index 076615cbe..d32e959b4 100644
--- a/OpenCL/m10100_a3.cl
+++ b/OpenCL/m10100_a3.cl
@@ -89,7 +89,7 @@ static void m10100m (u32 w[16], const u32 pw_len, __global pw_t *pws, __global k
 
     v0 ^= m;
 
-    int i;
+    u32 i;
     int j;
 
     for (i = 8, j = 2; i <= pw_len; i += 8, j += 2)
@@ -187,7 +187,7 @@ static void m10100s (u32 w[16], const u32 pw_len, __global pw_t *pws, __global k
 
     v0 ^= m;
 
-    int i;
+    u32 i;
     int j;
 
     for (i = 8, j = 2; i <= pw_len; i += 8, j += 2)