diff --git a/unittest/bitvector_test.cc b/unittest/bitvector_test.cc
index 54d849a3..a9b72833 100644
--- a/unittest/bitvector_test.cc
+++ b/unittest/bitvector_test.cc
@@ -24,6 +24,11 @@ const int kPrimeLimit = 1000;
 namespace {
 
 class BitVectorTest : public testing::Test {
+ protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+
  public:
   std::string OutputNameToPath(const std::string& name) {
     return file::JoinPath(FLAGS_test_tmpdir, name);
diff --git a/unittest/colpartition_test.cc b/unittest/colpartition_test.cc
index 140f06c2..46756651 100644
--- a/unittest/colpartition_test.cc
+++ b/unittest/colpartition_test.cc
@@ -27,7 +27,9 @@ class TestableColPartition : public ColPartition {
 
 class ColPartitionTest : public testing::Test {
  protected:
-  void SetUp() {}
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
 
   void TearDown() {}
 };
diff --git a/unittest/commandlineflags_test.cc b/unittest/commandlineflags_test.cc
index d767bc80..e97770b2 100644
--- a/unittest/commandlineflags_test.cc
+++ b/unittest/commandlineflags_test.cc
@@ -31,6 +31,10 @@ namespace {
 
 class CommandlineflagsTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   void TestParser(int argc, const char** const_argv) {
     TestParser("", argc, const_argv);
   }
diff --git a/unittest/dawg_test.cc b/unittest/dawg_test.cc
index dc035767..621fa7d2 100644
--- a/unittest/dawg_test.cc
+++ b/unittest/dawg_test.cc
@@ -27,6 +27,10 @@ namespace {
 // aka Directed Acyclic Word Graphs).
 class DawgTest : public testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   void LoadWordlist(const std::string& filename, std::set<std::string>* words) const {
     std::ifstream file(filename);
     if (file.is_open()) {
diff --git a/unittest/denorm_test.cc b/unittest/denorm_test.cc
index 861602fb..b1f75b9d 100644
--- a/unittest/denorm_test.cc
+++ b/unittest/denorm_test.cc
@@ -17,9 +17,12 @@
 namespace {
 
 class DENORMTest : public testing::Test {
- public:
-  void SetUp() {}
+ protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
 
+ public:
   void TearDown() {}
 
   void ExpectCorrectTransform(const DENORM& denorm, const TPOINT& src,
diff --git a/unittest/equationdetect_test.cc b/unittest/equationdetect_test.cc
index a22b10c8..69cf85ea 100644
--- a/unittest/equationdetect_test.cc
+++ b/unittest/equationdetect_test.cc
@@ -105,6 +105,7 @@ class EquationFinderTest : public testing::Test {
   string testdata_dir_;
 
   void SetUp() {
+    std::locale::global(std::locale(""));
     string tessdata_dir = file::JoinPath(FLAGS_test_srcdir, "tessdata");
     tesseract_.reset(new Tesseract());
     tesseract_->init_tesseract(tessdata_dir.c_str(), "eng", OEM_TESSERACT_ONLY);
diff --git a/unittest/heap_test.cc b/unittest/heap_test.cc
index 26046d50..4daae766 100644
--- a/unittest/heap_test.cc
+++ b/unittest/heap_test.cc
@@ -25,6 +25,11 @@ int test_data[] = {8, 1, 2, -4, 7, 9, 65536, 4, 9, 0};
 
 // The fixture for testing GenericHeap and DoublePtr.
 class HeapTest : public testing::Test {
+ protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
  public:
   virtual ~HeapTest();
   // Pushes the test data onto both the heap and the KDVector.
diff --git a/unittest/imagedata_test.cc b/unittest/imagedata_test.cc
index b5fb1df2..526a81fd 100644
--- a/unittest/imagedata_test.cc
+++ b/unittest/imagedata_test.cc
@@ -29,6 +29,10 @@ namespace {
 
 class ImagedataTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   ImagedataTest() {}
 
   // Creates a fake DocumentData, writes it to a file, and returns the filename.
diff --git a/unittest/indexmapbidi_test.cc b/unittest/indexmapbidi_test.cc
index 25f9eabf..0ac3951f 100644
--- a/unittest/indexmapbidi_test.cc
+++ b/unittest/indexmapbidi_test.cc
@@ -25,6 +25,11 @@ const int kPrimeLimit = 1000;
 namespace {
 
 class IndexMapBiDiTest : public testing::Test {
+ protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
  public:
   std::string OutputNameToPath(const std::string& name) {
     return file::JoinPath(FLAGS_test_tmpdir, name);
diff --git a/unittest/intsimdmatrix_test.cc b/unittest/intsimdmatrix_test.cc
index f767ad41..aec8db01 100644
--- a/unittest/intsimdmatrix_test.cc
+++ b/unittest/intsimdmatrix_test.cc
@@ -27,6 +27,10 @@ namespace {
 
 class IntSimdMatrixTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   // Makes a random weights matrix of the given size.
   GENERIC_2D_ARRAY<int8_t> InitRandom(int no, int ni) {
     GENERIC_2D_ARRAY<int8_t> a(no, ni, 0);
diff --git a/unittest/ligature_table_test.cc b/unittest/ligature_table_test.cc
index 3e37123e..5ada5758 100644
--- a/unittest/ligature_table_test.cc
+++ b/unittest/ligature_table_test.cc
@@ -24,6 +24,10 @@ const char kRenderableEngLigatureText[] = "fidelity effigy ſteep";
 
 class LigatureTableTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   static void SetUpTestCase() {
     FLAGS_fonts_dir = File::JoinPath(FLAGS_test_srcdir, "testdata");
     FLAGS_fontconfig_tmpdir = FLAGS_test_tmpdir;
diff --git a/unittest/linlsq_test.cc b/unittest/linlsq_test.cc
index c61e0453..8f41ca96 100644
--- a/unittest/linlsq_test.cc
+++ b/unittest/linlsq_test.cc
@@ -16,9 +16,12 @@
 namespace {
 
 class LLSQTest : public testing::Test {
- public:
-  void SetUp() {}
+ protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
 
+ public:
   void TearDown() {}
 
   void ExpectCorrectLine(const LLSQ& llsq, double m, double c, double rms,
diff --git a/unittest/lstm_test.h b/unittest/lstm_test.h
index 68a828ef..06c2320d 100644
--- a/unittest/lstm_test.h
+++ b/unittest/lstm_test.h
@@ -45,6 +45,10 @@ const int kBatchIterations = 1;
 // The fixture for testing LSTMTrainer.
 class LSTMTrainerTest : public testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   LSTMTrainerTest() {}
   std::string TestDataNameToPath(const std::string& name) {
     return file::JoinPath(TESTDATA_DIR,
diff --git a/unittest/matrix_test.cc b/unittest/matrix_test.cc
index 5bb8cb14..6774fa4c 100644
--- a/unittest/matrix_test.cc
+++ b/unittest/matrix_test.cc
@@ -22,6 +22,10 @@ namespace {
 
 class MatrixTest : public ::testing::Test {
  protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+
   // Fills src_ with data so it can pretend to be a tensor thus:
   //  dims_=[5, 4, 3, 2]
   //  array_=[0, 1, 2, ....119]
diff --git a/unittest/networkio_test.cc b/unittest/networkio_test.cc
index 8efe743a..aaa82093 100644
--- a/unittest/networkio_test.cc
+++ b/unittest/networkio_test.cc
@@ -12,6 +12,10 @@ namespace {
 
 class NetworkioTest : public ::testing::Test {
  protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+
   // Sets up an Array2d object of the given size, initialized to increasing
   // values starting with start.
   std::unique_ptr<Array2D<int>> SetupArray(int ysize, int xsize, int start) {
diff --git a/unittest/nthitem_test.cc b/unittest/nthitem_test.cc
index 670faf99..b242cc49 100644
--- a/unittest/nthitem_test.cc
+++ b/unittest/nthitem_test.cc
@@ -20,6 +20,11 @@ int test_data[] = {8, 1, 2, -4, 7, 9, 65536, 4, 9, 0, -32767, 6, 7};
 
 // The fixture for testing GenericHeap and DoublePtr.
 class NthItemTest : public testing::Test {
+ protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+
  public:
   virtual ~NthItemTest();
   // Pushes the test data onto the KDVector.
diff --git a/unittest/pango_font_info_test.cc b/unittest/pango_font_info_test.cc
index 875b57b3..fde4f34f 100644
--- a/unittest/pango_font_info_test.cc
+++ b/unittest/pango_font_info_test.cc
@@ -48,6 +48,10 @@ const char* kBadlyFormedHinWords[] = {
 
 class PangoFontInfoTest : public ::testing::Test {
  protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+
   // Creates a fake fonts.conf file that points to the testdata fonts for
   // fontconfig to initialize with.
   static void SetUpTestCase() {
diff --git a/unittest/qrsequence_test.cc b/unittest/qrsequence_test.cc
index 8ce3eba4..18f059e4 100644
--- a/unittest/qrsequence_test.cc
+++ b/unittest/qrsequence_test.cc
@@ -37,7 +37,12 @@ TEST(QRSequenceGenerator, GetBinaryReversedInteger) {
 }
 
 // Trivial test fixture for a parameterized test.
-class QRSequenceGeneratorTest : public ::testing::TestWithParam<int> {};
+class QRSequenceGeneratorTest : public ::testing::TestWithParam<int> {
+ protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+};
 
 TEST_P(QRSequenceGeneratorTest, GeneratesValidSequence) {
   const int kRangeSize = GetParam();
diff --git a/unittest/recodebeam_test.cc b/unittest/recodebeam_test.cc
index 1d1bc59a..b1736e01 100644
--- a/unittest/recodebeam_test.cc
+++ b/unittest/recodebeam_test.cc
@@ -69,6 +69,10 @@ const float kVi2ndScores[] = {0.01, 0.01, 0.01, 0.01, 0.01, 0.01, 0.01};
 
 class RecodeBeamTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   RecodeBeamTest() : lstm_dict_(&ccutil_) {}
   ~RecodeBeamTest() { lstm_dict_.End(); }
 
@@ -153,7 +157,7 @@ class RecodeBeamTest : public ::testing::Test {
                 !recoder_.IsValidFirstCode(labels[index])));
       EXPECT_NE(INVALID_UNICHAR_ID, uni_id)
           << "index=" << index << "/" << labels.size();
-		  // To the extent of truth_utf8, we expect decoded to match, but if
+      // To the extent of truth_utf8, we expect decoded to match, but if
       // transcription is shorter, that is OK too, as we may just be testing
       // that we get a valid sequence when padded with random data.
       if (uni_id != unichar_null_char_ && decoded.size() < truth_utf8.size())
diff --git a/unittest/rect_test.cc b/unittest/rect_test.cc
index 069ca7de..38f77eb8 100644
--- a/unittest/rect_test.cc
+++ b/unittest/rect_test.cc
@@ -17,7 +17,9 @@ namespace {
 
 class TBOXTest : public testing::Test {
  public:
-  void SetUp() {}
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
 
   void TearDown() {}
 };
diff --git a/unittest/scanutils_test.cc b/unittest/scanutils_test.cc
index 5d14924e..f54f87df 100644
--- a/unittest/scanutils_test.cc
+++ b/unittest/scanutils_test.cc
@@ -6,6 +6,10 @@ namespace {
 
 class ScanutilsTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   string TestDataNameToPath(const string& name) {
     return file::JoinPath(FLAGS_test_srcdir, "testdata/" + name);
   }
diff --git a/unittest/stats_test.cc b/unittest/stats_test.cc
index 6b0a7ae7..be692cfb 100644
--- a/unittest/stats_test.cc
+++ b/unittest/stats_test.cc
@@ -22,6 +22,7 @@ const int kTestData[] = {2, 0, 12, 1, 1, 2, 10, 1, 0, 0, 0, 2, 0, 4, 1, 1};
 class STATSTest : public testing::Test {
  public:
   void SetUp() {
+    std::locale::global(std::locale(""));
     stats_.set_range(0, 16);
     for (size_t i = 0; i < ARRAYSIZE(kTestData); ++i)
       stats_.add(i, kTestData[i]);
diff --git a/unittest/stridemap_test.cc b/unittest/stridemap_test.cc
index 2427eba0..d9b58755 100644
--- a/unittest/stridemap_test.cc
+++ b/unittest/stridemap_test.cc
@@ -10,6 +10,10 @@ namespace {
 
 class StridemapTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   // Sets up an Array2d object of the given size, initialized to increasing
   // values starting with start.
   std::unique_ptr<Array2D<int>> SetupArray(int ysize, int xsize, int start) {
diff --git a/unittest/stringrenderer_test.cc b/unittest/stringrenderer_test.cc
index 6841e490..c778b480 100644
--- a/unittest/stringrenderer_test.cc
+++ b/unittest/stringrenderer_test.cc
@@ -50,6 +50,10 @@ using tesseract::StringRenderer;
 
 class StringRendererTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   static void SetUpTestCase() {
     l_chooseDisplayProg(L_DISPLAY_WITH_XZGV);
     FLAGS_fonts_dir = TESTING_DIR;
diff --git a/unittest/tablefind_test.cc b/unittest/tablefind_test.cc
index a73544c3..06712475 100644
--- a/unittest/tablefind_test.cc
+++ b/unittest/tablefind_test.cc
@@ -66,6 +66,7 @@ class TestableTableFinder : public tesseract::TableFinder {
 class TableFinderTest : public testing::Test {
  protected:
   void SetUp() {
+    std::locale::global(std::locale(""));
     free_boxes_it_.set_to_list(&free_boxes_);
     finder_.reset(new TestableTableFinder());
     finder_->Init(1, ICOORD(0, 0), ICOORD(500, 500));
diff --git a/unittest/tablerecog_test.cc b/unittest/tablerecog_test.cc
index 55d60831..a9c19b25 100644
--- a/unittest/tablerecog_test.cc
+++ b/unittest/tablerecog_test.cc
@@ -71,6 +71,7 @@ class TestableStructuredTable : public tesseract::StructuredTable {
 class SharedTest : public testing::Test {
  protected:
   void SetUp() {
+    std::locale::global(std::locale(""));
     ICOORD bleft(0, 0);
     ICOORD tright(1000, 1000);
     text_grid_.reset(new ColPartitionGrid(5, bleft, tright));
diff --git a/unittest/tabvector_test.cc b/unittest/tabvector_test.cc
index d4f15fdd..9b78d6cb 100644
--- a/unittest/tabvector_test.cc
+++ b/unittest/tabvector_test.cc
@@ -21,7 +21,10 @@ namespace {
 
 class TabVectorTest : public testing::Test {
  protected:
-  void SetUp() { vector_.reset(); }
+  void SetUp() {
+    std::locale::global(std::locale(""));
+    vector_.reset();
+  }
 
   void TearDown() {}
 
diff --git a/unittest/tatweel_test.cc b/unittest/tatweel_test.cc
index 4f7ed920..422e2288 100644
--- a/unittest/tatweel_test.cc
+++ b/unittest/tatweel_test.cc
@@ -7,6 +7,10 @@ namespace {
 
 class TatweelTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   TatweelTest() {
     string filename = TestDataNameToPath("ara.wordlist");
     string wordlist;
diff --git a/unittest/tfile_test.cc b/unittest/tfile_test.cc
index d7f08d3d..9cad4ea9 100644
--- a/unittest/tfile_test.cc
+++ b/unittest/tfile_test.cc
@@ -23,6 +23,10 @@ namespace {
 
 class TfileTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   TfileTest() {}
 
   // Some data to serialize.
diff --git a/unittest/unicharcompress_test.cc b/unittest/unicharcompress_test.cc
index b36db1f2..a7eff561 100644
--- a/unittest/unicharcompress_test.cc
+++ b/unittest/unicharcompress_test.cc
@@ -27,6 +27,10 @@ namespace {
 
 class UnicharcompressTest : public ::testing::Test {
  protected:
+  void SetUp() {
+    std::locale::global(std::locale(""));
+  }
+
   // Loads and compresses the given unicharset.
   void LoadUnicharset(const std::string& unicharset_name) {
     std::string radical_stroke_file =
diff --git a/unittest/unicharset_test.cc b/unittest/unicharset_test.cc
index 927a60aa..f1622fe3 100644
--- a/unittest/unicharset_test.cc
+++ b/unittest/unicharset_test.cc
@@ -19,6 +19,13 @@ using testing::ElementsAreArray;
 
 namespace {
 
+class UnicharsetTest : public ::testing::Test {
+ protected:
+  void SetUp() override {
+    std::locale::global(std::locale(""));
+  }
+};
+
 TEST(UnicharsetTest, Basics) {
   // This test verifies basic insertion, unichar_to_id, and encode.
   UNICHARSET u;