diff --git a/tests/test-139.ispc b/tests/test-139.ispc
index 5e2c8aac..f86ac911 100644
--- a/tests/test-139.ispc
+++ b/tests/test-139.ispc
@@ -4,12 +4,15 @@ export uniform int width() { return programCount; }
 
 export void f_f(uniform float RET[], uniform float aFOO[]) {
     float a = aFOO[programIndex&0x3]; 
-    RET[programIndex] = exp(a); 
-}
 
-export void result(uniform float RET[]) {
-    RET[0] = RET[4] = RET[8] = RET[12] = 0x1.5bf0a8p+1;
-    RET[1] = RET[5] = RET[9] = RET[13] = 0x1.d8e64cp+2;
-    RET[2] = RET[6] = RET[10] = RET[14] = 0x1.415e5cp+4;
-    RET[3] = RET[7] = RET[11] = RET[15] = 0x1.b4c904p+5;
+    uniform float expected[4] = { 0x1.5bf0a8p+1, 0x1.d8e64cp+2, 0x1.415e5cp+4, 0x1.b4c904p+5 };
+    float v = exp(a);
+
+    RET[programIndex] = 0;
+    if (abs((v - expected[programIndex & 0x3]) / expected[programIndex & 0x3]) > 1e-5)
+        RET[programIndex] = 1;
+}
+ 
+ export void result(uniform float RET[]) {
+     RET[programIndex] = 0;
 }