diff --git a/src/ftxui/dom/canvas_test.cpp b/src/ftxui/dom/canvas_test.cpp
index 1f8180c..010416a 100644
--- a/src/ftxui/dom/canvas_test.cpp
+++ b/src/ftxui/dom/canvas_test.cpp
@@ -14,7 +14,7 @@ namespace ftxui {
 namespace {
 uint32_t Hash(const std::string s) {
   uint32_t hash = 0;
-  for (auto c : s) {
+  for (uint8_t c : s) {
     hash += c;
     hash *= 7;
   }
@@ -37,7 +37,7 @@ TEST(CanvasTest, GoldPoint) {
   });
   Screen screen(30, 10);
   Render(screen, element);
-  EXPECT_EQ(Hash(screen.ToString()), 2143518726);
+  EXPECT_EQ(Hash(screen.ToString()), 2085952774U) << screen.ToString();
 }
 
 TEST(CanvasTest, GoldPointColor) {
@@ -52,7 +52,7 @@ TEST(CanvasTest, GoldPointColor) {
   });
   Screen screen(30, 10);
   Render(screen, element);
-  EXPECT_EQ(Hash(screen.ToString()), 1264423298);
+  EXPECT_EQ(Hash(screen.ToString()), 2295070594U) << screen.ToString();
 }
 
 TEST(CanvasTest, GoldBlock) {
@@ -70,7 +70,7 @@ TEST(CanvasTest, GoldBlock) {
   });
   Screen screen(30, 10);
   Render(screen, element);
-  EXPECT_EQ(Hash(screen.ToString()), 3826174883);
+  EXPECT_EQ(Hash(screen.ToString()), 2625314979U) << screen.ToString();
 }
 
 TEST(CanvasTest, GoldBlockColor) {
@@ -85,7 +85,7 @@ TEST(CanvasTest, GoldBlockColor) {
   });
   Screen screen(30, 10);
   Render(screen, element);
-  EXPECT_EQ(Hash(screen.ToString()), 3048712696);
+  EXPECT_EQ(Hash(screen.ToString()), 8392696U) << screen.ToString();
 }
 
 TEST(CanvasTest, GoldText) {