diff --git a/src/ccmain/par_control.cpp b/src/ccmain/par_control.cpp
index 0f916c6e..efad3355 100644
--- a/src/ccmain/par_control.cpp
+++ b/src/ccmain/par_control.cpp
@@ -55,7 +55,7 @@ void Tesseract::PrerecAllWordsPar(const std::vector<WordData> &words) {
 #  pragma omp parallel for num_threads(10)
 #endif // _OPENMP
     // NOLINTNEXTLINE(modernize-loop-convert)
-    for (auto b = 0; b < blobs.size(); ++b) {
+    for (size_t b = 0; b < blobs.size(); ++b) {
       *blobs[b].choices =
           blobs[b].tesseract->classify_blob(blobs[b].blob, "par", ScrollView::WHITE, nullptr);
     }
diff --git a/src/lstm/parallel.cpp b/src/lstm/parallel.cpp
index 5b3fd1d4..2713314c 100644
--- a/src/lstm/parallel.cpp
+++ b/src/lstm/parallel.cpp
@@ -137,7 +137,7 @@ bool Parallel::Backward(bool debug, const NetworkIO &fwd_deltas, NetworkScratch
 #ifdef _OPENMP
 #  pragma omp parallel for num_threads(stack_size)
 #endif
-    for (auto i = 0; i < stack_size; ++i) {
+    for (unsigned i = 0; i < stack_size; ++i) {
       stack_[i]->Backward(debug, *in_deltas[i], scratch, i == 0 ? back_deltas : out_deltas[i]);
     }
     if (needs_to_backprop_) {