diff --git a/libs/gui/tests/SurfaceTexture_test.cpp b/libs/gui/tests/SurfaceTexture_test.cpp
index 16280d2..fdb6f52 100644
--- a/libs/gui/tests/SurfaceTexture_test.cpp
+++ b/libs/gui/tests/SurfaceTexture_test.cpp
@@ -273,8 +273,12 @@
         *outPgm = program;
     }
 
+    static int abs(int value) {
+        return value > 0 ? value : -value;
+    }
+
     ::testing::AssertionResult checkPixel(int x, int y, int r,
-            int g, int b, int a) {
+            int g, int b, int a, int tolerance=2) {
         GLubyte pixel[4];
         String8 msg;
         glReadPixels(x, y, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, pixel);
@@ -288,22 +292,22 @@
             return ::testing::AssertionFailure(
                     ::testing::Message(msg.string()));
         }
-        if (r >= 0 && GLubyte(r) != pixel[0]) {
+        if (r >= 0 && abs(r - int(pixel[0])) > tolerance) {
             msg += String8::format("r(%d isn't %d)", pixel[0], r);
         }
-        if (g >= 0 && GLubyte(g) != pixel[1]) {
+        if (g >= 0 && abs(g - int(pixel[1])) > tolerance) {
             if (!msg.isEmpty()) {
                 msg += " ";
             }
             msg += String8::format("g(%d isn't %d)", pixel[1], g);
         }
-        if (b >= 0 && GLubyte(b) != pixel[2]) {
+        if (b >= 0 && abs(b - int(pixel[2])) > tolerance) {
             if (!msg.isEmpty()) {
                 msg += " ";
             }
             msg += String8::format("b(%d isn't %d)", pixel[2], b);
         }
-        if (a >= 0 && GLubyte(a) != pixel[3]) {
+        if (a >= 0 && abs(a - int(pixel[3])) > tolerance) {
             if (!msg.isEmpty()) {
                 msg += " ";
             }