diff --git a/tests/cpu/AVX2_tests.cpp b/tests/cpu/AVX2_tests.cpp
index 32c2bdc63e..1d8373fc90 100644
--- a/tests/cpu/AVX2_tests.cpp
+++ b/tests/cpu/AVX2_tests.cpp
@@ -161,8 +161,9 @@ void testConvert_InBitDepth(OCIO::BitDepth outBD)
 
 DEFINE_SIMD_TEST(packed_uint8_to_float_test)
 {
-    std::vector<uint8_t> inImage(256);
-    std::vector<float> outImage(256);
+    size_t maxValue = OCIO::BitDepthInfo<OCIO::BIT_DEPTH_UINT8>::maxValue + 1;
+    std::vector<uint8_t> inImage(maxValue);
+    std::vector<float> outImage(maxValue);
 
     for (unsigned i = 0; i < inImage.size(); i++)
     {
diff --git a/tests/cpu/AVX512_tests.cpp b/tests/cpu/AVX512_tests.cpp
index 8e251074a8..8b8e6f9cd7 100644
--- a/tests/cpu/AVX512_tests.cpp
+++ b/tests/cpu/AVX512_tests.cpp
@@ -186,8 +186,9 @@ void testConvert_InBitDepth(OCIO::BitDepth outBD)
 
 DEFINE_SIMD_TEST(packed_uint8_to_float_test)
 {
-    std::vector<uint8_t> inImage(256);
-    std::vector<float> outImage(256);
+    size_t maxValue = OCIO::BitDepthInfo<OCIO::BIT_DEPTH_UINT8>::maxValue + 1;
+    std::vector<uint8_t> inImage(maxValue);
+    std::vector<float> outImage(maxValue);
 
     for (unsigned i = 0; i < inImage.size(); i++)
     {
diff --git a/tests/cpu/AVX_tests.cpp b/tests/cpu/AVX_tests.cpp
index e1872145a1..a88b52a8a1 100644
--- a/tests/cpu/AVX_tests.cpp
+++ b/tests/cpu/AVX_tests.cpp
@@ -161,8 +161,9 @@ void testConvert_InBitDepth(OCIO::BitDepth outBD)
 
 DEFINE_SIMD_TEST(packed_uint8_to_float_test)
 {
-    std::vector<uint8_t> inImage(256);
-    std::vector<float> outImage(256);
+    size_t maxValue = OCIO::BitDepthInfo<OCIO::BIT_DEPTH_UINT8>::maxValue + 1;
+    std::vector<uint8_t> inImage(maxValue);
+    std::vector<float> outImage(maxValue);
 
     for (unsigned i = 0; i < inImage.size(); i++)
     {
diff --git a/tests/cpu/SSE2_tests.cpp b/tests/cpu/SSE2_tests.cpp
index 7c6d028b83..b7d2961cf5 100644
--- a/tests/cpu/SSE2_tests.cpp
+++ b/tests/cpu/SSE2_tests.cpp
@@ -150,8 +150,9 @@ void testConvert_InBitDepth(OCIO::BitDepth outBD)
 
 DEFINE_SIMD_TEST(packed_uint8_to_float_test)
 {
-    std::vector<uint8_t> inImage(256);
-    std::vector<float> outImage(256);
+    size_t maxValue = OCIO::BitDepthInfo<OCIO::BIT_DEPTH_UINT8>::maxValue + 1;
+    std::vector<uint8_t> inImage(maxValue);
+    std::vector<float> outImage(maxValue);
 
     for (unsigned i = 0; i < inImage.size(); i++)
     {