diff --git a/tests/foreach-mask-1.ispc b/tests/foreach-mask-1.ispc
index 2f462b48..ee4b1b1e 100644
--- a/tests/foreach-mask-1.ispc
+++ b/tests/foreach-mask-1.ispc
@@ -10,8 +10,10 @@ export void f_f(uniform float RET[], uniform float aFOO[]) {
 
     // make sure we reset the func mask in the foreach loop...
     if ((int)aFOO[programIndex] & 1)
-        foreach (i = 0 ... programCount+3)
-            val[i] += aFOO[i] - 1;
+        foreach (i = 0 ... programCount+3) {
+            int ic = min(i, programCount-1);
+            val[i] += aFOO[ic] - 1 + i-ic;
+        }
 
     RET[programIndex] = val[3+programIndex]; 
 }
diff --git a/tests/foreach-mask.ispc b/tests/foreach-mask.ispc
index 0d01b16a..f6000a71 100644
--- a/tests/foreach-mask.ispc
+++ b/tests/foreach-mask.ispc
@@ -5,8 +5,10 @@ export uniform int width() { return programCount; }
 // make sure we reset the func mask in the foreach loop...
 
 void update(uniform float val[], const uniform float a[]) {
-    foreach (i = 0 ... programCount+3)
-        val[i] += a[i] - 1;
+    foreach (i = 0 ... programCount+3) {
+        int ic = min(i, programCount-1);
+        val[i] += a[ic] - 1 + i-ic;
+    }
 }
 
 export void f_f(uniform float RET[], uniform float aFOO[]) {