diff --git a/test/framework/array.h b/test/framework/array.h
index 1b392ad652ad1c700c85b6673d34d52537519da2..4a566053a2bed828c86bfe67320d73eec98228e1 100644
--- a/test/framework/array.h
+++ b/test/framework/array.h
@@ -309,21 +309,23 @@ class Array2D : public TwoDimensional<ElementType> {
 };  // end of class Array2D<ElementType>
 
 /// Compares two \ref Array2D objects for equality.
-#define EXPECT_EQ_ARRAY2D(lhs, rhs)                                 \
-  do {                                                              \
-    ASSERT_EQ((lhs).width(), (rhs).width())                         \
-        << "Mismatch in width." << std::endl;                       \
-    ASSERT_EQ((lhs).height(), (rhs).height())                       \
-        << "Mismatch in height." << std::endl;                      \
-    ASSERT_EQ((lhs).channels(), (rhs).channels())                   \
-        << "Mismatch in channels." << std::endl;                    \
-    auto mismatch = (lhs).compare_to((rhs));                        \
-    if (mismatch) {                                                 \
-      auto [row, col] = *mismatch;                                  \
-      GTEST_FAIL() << "Mismatch at (row=" << row << ", col=" << col \
-                   << "): " << (lhs).at(row, col)[0] << " vs "      \
-                   << (rhs).at(row, col)[0] << "." << std::endl;    \
-    }                                                               \
+#define EXPECT_EQ_ARRAY2D(lhs, rhs)                                          \
+  do {                                                                       \
+    ASSERT_EQ((lhs).width(), (rhs).width())                                  \
+        << "Mismatch in width." << std::endl;                                \
+    ASSERT_EQ((lhs).height(), (rhs).height())                                \
+        << "Mismatch in height." << std::endl;                               \
+    ASSERT_EQ((lhs).channels(), (rhs).channels())                            \
+        << "Mismatch in channels." << std::endl;                             \
+    auto mismatch = (lhs).compare_to((rhs));                                 \
+    if (mismatch) {                                                          \
+      auto [row, col] = *mismatch;                                           \
+      GTEST_FAIL() << "Mismatch at (row=" << row << ", col=" << col          \
+                   << "): " << std::hex << std::showbase                     \
+                   << static_cast<uint64_t>((lhs).at(row, col)[0]) << " vs " \
+                   << static_cast<uint64_t>((rhs).at(row, col)[0]) << "."    \
+                   << std::endl;                                             \
+    }                                                                        \
   } while (0 != 0)
 
 /// Compares two \ref Array2D objects for inequality.
diff --git a/test/framework/test_array2d.cpp b/test/framework/test_array2d.cpp
index a26c25bd19de5b0c651cd2a0a34b76303df2c6a9..adbeaa7cdeaf120b2aff9625b7ad4222bbc00b6c 100644
--- a/test/framework/test_array2d.cpp
+++ b/test/framework/test_array2d.cpp
@@ -296,7 +296,7 @@ TEST(Array2D, ExpectEq_NotEqual_Data) {
     }
   };
 
-  EXPECT_FATAL_FAILURE(Test::test(), "Mismatch at (row=0, col=0): 0 vs 42.");
+  EXPECT_FATAL_FAILURE(Test::test(), "Mismatch at (row=0, col=0): 0 vs 0x2a.");
 }
 
 /// Tests that EXPECT_NE_ARRAY2D() macro works for equal objects.