diff --git a/src/backends/reference/test/RefPerAxisIteratorTests.cpp b/src/backends/reference/test/RefPerAxisIteratorTests.cpp
index 06d2703..92b828e 100644
--- a/src/backends/reference/test/RefPerAxisIteratorTests.cpp
+++ b/src/backends/reference/test/RefPerAxisIteratorTests.cpp
@@ -17,7 +17,7 @@
     CHECK(vec1.size() == vec2.size());
 
     bool mismatch = false;
-    for (uint i = 0; i < vec1.size(); ++i)
+    for (uint32_t i = 0; i < vec1.size(); ++i)
     {
         if (vec1[i] != vec2[i])
         {
diff --git a/src/backends/reference/test/RefPerChannelDecoderTests.cpp b/src/backends/reference/test/RefPerChannelDecoderTests.cpp
index 90d6afc..df68aee 100644
--- a/src/backends/reference/test/RefPerChannelDecoderTests.cpp
+++ b/src/backends/reference/test/RefPerChannelDecoderTests.cpp
@@ -17,7 +17,7 @@
     CHECK(vec1.size() == vec2.size());
 
     bool mismatch = false;
-    for (uint i = 0; i < vec1.size(); ++i)
+    for (uint32_t i = 0; i < vec1.size(); ++i)
     {
         if (vec1[i] != vec2[i])
         {