diff --git a/util/stdlib/string_number_conversion.cc b/util/stdlib/string_number_conversion.cc
index 859a8333..64211844 100644
--- a/util/stdlib/string_number_conversion.cc
+++ b/util/stdlib/string_number_conversion.cc
@@ -97,15 +97,34 @@ struct StringToUnsignedIntTraits
   }
 };
 
-struct StringToInt64Traits
-    : public StringToSignedIntegerTraits<int64_t, int64_t> {
+struct StringToLongTraits
+    : public StringToSignedIntegerTraits<long, long long> {
   static LongType Convert(const char* str, char** end, int base) {
     return strtoll(str, end, base);
   }
 };
 
-struct StringToUnsignedInt64Traits
-    : public StringToUnsignedIntegerTraits<uint64_t, uint64_t> {
+struct StringToUnsignedLongTraits
+    : public StringToUnsignedIntegerTraits<unsigned long, unsigned long long> {
+  static LongType Convert(const char* str, char** end, int base) {
+    if (str[0] == '-') {
+      *end = const_cast<char*>(str);
+      return 0;
+    }
+    return strtoull(str, end, base);
+  }
+};
+
+struct StringToLongLongTraits
+    : public StringToSignedIntegerTraits<long long, long long> {
+  static LongType Convert(const char* str, char** end, int base) {
+    return strtoll(str, end, base);
+  }
+};
+
+struct StringToUnsignedLongLongTraits
+    : public StringToUnsignedIntegerTraits<unsigned long long,
+                                           unsigned long long> {
   static LongType Convert(const char* str, char** end, int base) {
     if (str[0] == '-') {
       *end = const_cast<char*>(str);
@@ -136,7 +155,7 @@ bool StringToIntegerInternal(const std::string& string,
       end != string.data() + string.length()) {
     return false;
   }
-  *number = result;
+  *number = static_cast<IntType>(result);
   return true;
 }
 
@@ -152,12 +171,21 @@ bool StringToNumber(const std::string& string, unsigned int* number) {
   return StringToIntegerInternal<StringToUnsignedIntTraits>(string, number);
 }
 
-bool StringToNumber(const std::string& string, int64_t* number) {
-  return StringToIntegerInternal<StringToInt64Traits>(string, number);
+bool StringToNumber(const std::string& string, long* number) {
+  return StringToIntegerInternal<StringToLongTraits>(string, number);
 }
 
-bool StringToNumber(const std::string& string, uint64_t* number) {
-  return StringToIntegerInternal<StringToUnsignedInt64Traits>(string, number);
+bool StringToNumber(const std::string& string, unsigned long* number) {
+  return StringToIntegerInternal<StringToUnsignedLongTraits>(string, number);
+}
+
+bool StringToNumber(const std::string& string, long long* number) {
+  return StringToIntegerInternal<StringToLongLongTraits>(string, number);
+}
+
+bool StringToNumber(const std::string& string, unsigned long long* number) {
+  return StringToIntegerInternal<StringToUnsignedLongLongTraits>(string,
+                                                                 number);
 }
 
 }  // namespace crashpad
diff --git a/util/stdlib/string_number_conversion.h b/util/stdlib/string_number_conversion.h
index b5f1d44a..69e7fdd6 100644
--- a/util/stdlib/string_number_conversion.h
+++ b/util/stdlib/string_number_conversion.h
@@ -56,8 +56,10 @@ namespace crashpad {
 //!     where such prefix recognition is desirable.
 bool StringToNumber(const std::string& string, int* number);
 bool StringToNumber(const std::string& string, unsigned int* number);
-bool StringToNumber(const std::string& string, int64_t* number);
-bool StringToNumber(const std::string& string, uint64_t* number);
+bool StringToNumber(const std::string& string, long* number);
+bool StringToNumber(const std::string& string, unsigned long* number);
+bool StringToNumber(const std::string& string, long long* number);
+bool StringToNumber(const std::string& string, unsigned long long* number);
 //! \}
 
 }  // namespace crashpad
diff --git a/util/stdlib/string_number_conversion_test.cc b/util/stdlib/string_number_conversion_test.cc
index 689b4ad5..760dc4a8 100644
--- a/util/stdlib/string_number_conversion_test.cc
+++ b/util/stdlib/string_number_conversion_test.cc
@@ -16,30 +16,39 @@
 
 #include <sys/types.h>
 
+#include <array>
 #include <limits>
+#include <type_traits>
 
 #include "base/stl_util.h"
 #include "gtest/gtest.h"
 
-namespace crashpad {
-namespace test {
-namespace {
+#define STRINGIFY(a) STR(a)
+#define STR(a) #a
 
-TEST(StringNumberConversion, StringToInt) {
-  static constexpr struct {
-    const char* string;
-    bool valid;
-    int value;
-  } kTestData[] = {
+template <typename TValueType>
+struct TestSpecification {
+  const char* string;
+  bool valid;
+  TValueType value;
+};
+
+// Signed 32-bit test data
+template <typename TIntType,
+          typename std::enable_if<std::is_integral<TIntType>::value &&
+                                  std::is_signed<TIntType>::value &&
+                                  (sizeof(TIntType) == 4)>::type* = nullptr>
+static constexpr std::array<TestSpecification<TIntType>, 61> kTestDataFunc() {
+  return {{
       {"", false, 0},
       {"0", true, 0},
       {"1", true, 1},
-      {"2147483647", true, std::numeric_limits<int>::max()},
+      {"2147483647", true, std::numeric_limits<TIntType>::max()},
       {"2147483648", false, 0},
       {"4294967295", false, 0},
       {"4294967296", false, 0},
       {"-1", true, -1},
-      {"-2147483648", true, std::numeric_limits<int>::min()},
+      {"-2147483648", true, std::numeric_limits<TIntType>::min()},
       {"-2147483649", false, 0},
       {"00", true, 0},
       {"01", true, 1},
@@ -50,12 +59,12 @@ TEST(StringNumberConversion, StringToInt) {
       {"+0x20", true, 32},
       {"0xf", true, 15},
       {"0xg", false, 0},
-      {"0x7fffffff", true, std::numeric_limits<int>::max()},
-      {"0x7FfFfFfF", true, std::numeric_limits<int>::max()},
+      {"0x7fffffff", true, std::numeric_limits<TIntType>::max()},
+      {"0x7FfFfFfF", true, std::numeric_limits<TIntType>::max()},
       {"0x80000000", false, 0},
       {"0xFFFFFFFF", false, 0},
       {"-0x7fffffff", true, -2147483647},
-      {"-0x80000000", true, std::numeric_limits<int>::min()},
+      {"-0x80000000", true, std::numeric_limits<TIntType>::min()},
       {"-0x80000001", false, 0},
       {"-0xffffffff", false, 0},
       {"0x100000000", false, 0},
@@ -92,45 +101,22 @@ TEST(StringNumberConversion, StringToInt) {
       {"9223372036854775809", false, 0},
       {"18446744073709551615", false, 0},
       {"18446744073709551616", false, 0},
-  };
-
-  for (size_t index = 0; index < base::size(kTestData); ++index) {
-    int value;
-    bool valid = StringToNumber(kTestData[index].string, &value);
-    if (kTestData[index].valid) {
-      EXPECT_TRUE(valid) << "index " << index << ", string "
-                         << kTestData[index].string;
-      if (valid) {
-        EXPECT_EQ(value, kTestData[index].value)
-            << "index " << index << ", string " << kTestData[index].string;
-      }
-    } else {
-      EXPECT_FALSE(valid) << "index " << index << ", string "
-                          << kTestData[index].string << ", value " << value;
-    }
-  }
-
-  // Ensure that embedded NUL characters are treated as bad input. The string
-  // is split to avoid MSVC warning:
-  //   "decimal digit terminates octal escape sequence".
-  static constexpr char input[] = "6\000" "6";
-  std::string input_string(input, base::size(input) - 1);
-  int output;
-  EXPECT_FALSE(StringToNumber(input_string, &output));
+  }};
 }
 
-TEST(StringNumberConversion, StringToUnsignedInt) {
-  static constexpr struct {
-    const char* string;
-    bool valid;
-    unsigned int value;
-  } kTestData[] = {
+// Unsigned 32-bit test data
+template <typename TIntType,
+          typename std::enable_if<std::is_integral<TIntType>::value &&
+                                  !std::is_signed<TIntType>::value &&
+                                  (sizeof(TIntType) == 4)>::type* = nullptr>
+static constexpr std::array<TestSpecification<TIntType>, 61> kTestDataFunc() {
+  return {{
       {"", false, 0},
       {"0", true, 0},
       {"1", true, 1},
       {"2147483647", true, 2147483647},
       {"2147483648", true, 2147483648},
-      {"4294967295", true, std::numeric_limits<unsigned int>::max()},
+      {"4294967295", true, std::numeric_limits<TIntType>::max()},
       {"4294967296", false, 0},
       {"-1", false, 0},
       {"-2147483648", false, 0},
@@ -186,9 +172,121 @@ TEST(StringNumberConversion, StringToUnsignedInt) {
       {"9223372036854775809", false, 0},
       {"18446744073709551615", false, 0},
       {"18446744073709551616", false, 0},
-  };
+  }};
+}
 
-  for (size_t index = 0; index < base::size(kTestData); ++index) {
+// Signed 64-bit test data
+template <typename TIntType,
+          typename std::enable_if<std::is_integral<TIntType>::value &&
+                                  std::is_signed<TIntType>::value &&
+                                  (sizeof(TIntType) == 8)>::type* = nullptr>
+static constexpr std::array<TestSpecification<TIntType>, 24> kTestDataFunc() {
+  return {{
+      {"", false, 0},
+      {"0", true, 0},
+      {"1", true, 1},
+      {"2147483647", true, 2147483647},
+      {"2147483648", true, 2147483648},
+      {"4294967295", true, 4294967295},
+      {"4294967296", true, 4294967296},
+      {"9223372036854775807", true, std::numeric_limits<TIntType>::max()},
+      {"9223372036854775808", false, 0},
+      {"18446744073709551615", false, 0},
+      {"18446744073709551616", false, 0},
+      {"-1", true, -1},
+      {"-2147483648", true, INT64_C(-2147483648)},
+      {"-2147483649", true, INT64_C(-2147483649)},
+      {"-9223372036854775808", true, std::numeric_limits<TIntType>::min()},
+      {"-9223372036854775809", false, 0},
+      {"0x7fffffffffffffff", true, std::numeric_limits<TIntType>::max()},
+      {"0x8000000000000000", false, 0},
+      {"0xffffffffffffffff", false, 0},
+      {"0x10000000000000000", false, 0},
+      {"-0x7fffffffffffffff", true, -9223372036854775807},
+      {"-0x8000000000000000", true, std::numeric_limits<TIntType>::min()},
+      {"-0x8000000000000001", false, 0},
+      {"0x7Fffffffffffffff", true, std::numeric_limits<TIntType>::max()},
+  }};
+}
+
+// Unsigned 64-bit test data
+template <typename TIntType,
+          typename std::enable_if<std::is_integral<TIntType>::value &&
+                                  !std::is_signed<TIntType>::value &&
+                                  (sizeof(TIntType) == 8)>::type* = nullptr>
+static constexpr std::array<TestSpecification<TIntType>, 25> kTestDataFunc() {
+  return {{
+      {"", false, 0},
+      {"0", true, 0},
+      {"1", true, 1},
+      {"2147483647", true, 2147483647},
+      {"2147483648", true, 2147483648},
+      {"4294967295", true, 4294967295},
+      {"4294967296", true, 4294967296},
+      {"9223372036854775807", true, 9223372036854775807},
+      {"9223372036854775808", true, 9223372036854775808u},
+      {"18446744073709551615", true, std::numeric_limits<TIntType>::max()},
+      {"18446744073709551616", false, 0},
+      {"-1", false, 0},
+      {"-2147483648", false, 0},
+      {"-2147483649", false, 0},
+      {"-2147483648", false, 0},
+      {"-9223372036854775808", false, 0},
+      {"-9223372036854775809", false, 0},
+      {"0x7fffffffffffffff", true, 9223372036854775807},
+      {"0x8000000000000000", true, 9223372036854775808u},
+      {"0xffffffffffffffff", true, std::numeric_limits<TIntType>::max()},
+      {"0x10000000000000000", false, 0},
+      {"-0x7fffffffffffffff", false, 0},
+      {"-0x8000000000000000", false, 0},
+      {"-0x8000000000000001", false, 0},
+      {"0xFfffffffffffffff", true, std::numeric_limits<TIntType>::max()},
+  }};
+}
+
+// This string is split to avoid MSVC warning:
+//   "decimal digit terminates octal escape sequence".
+static constexpr char kEmbeddedNullInputRaw[] = "6\000" "6";
+
+namespace crashpad {
+namespace test {
+namespace {
+
+TEST(StringNumberConversion, StringToInt) {
+  static_assert(sizeof(int) == 4, "Test only configured for 32-bit int.");
+  static constexpr auto kTestData = kTestDataFunc<int>();
+
+  for (size_t index = 0; index < kTestData.size(); ++index) {
+    int value;
+    bool valid = StringToNumber(kTestData[index].string, &value);
+    if (kTestData[index].valid) {
+      EXPECT_TRUE(valid) << "index " << index << ", string "
+                         << kTestData[index].string;
+      if (valid) {
+        EXPECT_EQ(value, kTestData[index].value)
+            << "index " << index << ", string " << kTestData[index].string;
+      }
+    } else {
+      EXPECT_FALSE(valid) << "index " << index << ", string "
+                          << kTestData[index].string << ", value " << value;
+    }
+  }
+
+  // Ensure that embedded NUL characters are treated as bad input. The string
+  // is split to avoid MSVC warning:
+  //   "decimal digit terminates octal escape sequence".
+  int output;
+  std::string kEmbeddedNullInput(kEmbeddedNullInputRaw,
+                                 base::size(kEmbeddedNullInputRaw) - 1);
+  EXPECT_FALSE(StringToNumber(kEmbeddedNullInput, &output));
+}
+
+TEST(StringNumberConversion, StringToUnsignedInt) {
+  static_assert(sizeof(unsigned int) == 4,
+                "Test only configured for 32-bit unsigned int.");
+  static constexpr auto kTestData = kTestDataFunc<unsigned int>();
+
+  for (size_t index = 0; index < kTestData.size(); ++index) {
     unsigned int value;
     bool valid = StringToNumber(kTestData[index].string, &value);
     if (kTestData[index].valid) {
@@ -207,46 +305,20 @@ TEST(StringNumberConversion, StringToUnsignedInt) {
   // Ensure that embedded NUL characters are treated as bad input. The string
   // is split to avoid MSVC warning:
   //   "decimal digit terminates octal escape sequence".
-  static constexpr char input[] = "6\000" "6";
-  std::string input_string(input, base::size(input) - 1);
   unsigned int output;
-  EXPECT_FALSE(StringToNumber(input_string, &output));
+  std::string kEmbeddedNullInput(kEmbeddedNullInputRaw,
+                                 base::size(kEmbeddedNullInputRaw) - 1);
+  EXPECT_FALSE(StringToNumber(kEmbeddedNullInput, &output));
 }
 
-TEST(StringNumberConversion, StringToInt64) {
-  static constexpr struct {
-    const char* string;
-    bool valid;
-    int64_t value;
-  } kTestData[] = {
-      {"", false, 0},
-      {"0", true, 0},
-      {"1", true, 1},
-      {"2147483647", true, 2147483647},
-      {"2147483648", true, 2147483648},
-      {"4294967295", true, 4294967295},
-      {"4294967296", true, 4294967296},
-      {"9223372036854775807", true, std::numeric_limits<int64_t>::max()},
-      {"9223372036854775808", false, 0},
-      {"18446744073709551615", false, 0},
-      {"18446744073709551616", false, 0},
-      {"-1", true, -1},
-      {"-2147483648", true, INT64_C(-2147483648)},
-      {"-2147483649", true, INT64_C(-2147483649)},
-      {"-9223372036854775808", true, std::numeric_limits<int64_t>::min()},
-      {"-9223372036854775809", false, 0},
-      {"0x7fffffffffffffff", true, std::numeric_limits<int64_t>::max()},
-      {"0x8000000000000000", false, 0},
-      {"0xffffffffffffffff", false, 0},
-      {"0x10000000000000000", false, 0},
-      {"-0x7fffffffffffffff", true, -9223372036854775807},
-      {"-0x8000000000000000", true, std::numeric_limits<int64_t>::min()},
-      {"-0x8000000000000001", false, 0},
-      {"0x7Fffffffffffffff", true, std::numeric_limits<int64_t>::max()},
-  };
+TEST(StringNumberConversion, StringToLong) {
+  static_assert(
+      sizeof(long) == 4 || sizeof(long) == 8,
+      "Test not configured for " STRINGIFY(__SIZEOF_LONG__) "-byte long");
+  static constexpr auto kTestData = kTestDataFunc<long>();
 
-  for (size_t index = 0; index < base::size(kTestData); ++index) {
-    int64_t value;
+  for (size_t index = 0; index < kTestData.size(); ++index) {
+    long value;
     bool valid = StringToNumber(kTestData[index].string, &value);
     if (kTestData[index].valid) {
       EXPECT_TRUE(valid) << "index " << index << ", string "
@@ -262,41 +334,58 @@ TEST(StringNumberConversion, StringToInt64) {
   }
 }
 
-TEST(StringNumberConversion, StringToUnsignedInt64) {
-  static constexpr struct {
-    const char* string;
-    bool valid;
-    uint64_t value;
-  } kTestData[] = {
-      {"", false, 0},
-      {"0", true, 0},
-      {"1", true, 1},
-      {"2147483647", true, 2147483647},
-      {"2147483648", true, 2147483648},
-      {"4294967295", true, 4294967295},
-      {"4294967296", true, 4294967296},
-      {"9223372036854775807", true, 9223372036854775807},
-      {"9223372036854775808", true, 9223372036854775808u},
-      {"18446744073709551615", true, std::numeric_limits<uint64_t>::max()},
-      {"18446744073709551616", false, 0},
-      {"-1", false, 0},
-      {"-2147483648", false, 0},
-      {"-2147483649", false, 0},
-      {"-2147483648", false, 0},
-      {"-9223372036854775808", false, 0},
-      {"-9223372036854775809", false, 0},
-      {"0x7fffffffffffffff", true, 9223372036854775807},
-      {"0x8000000000000000", true, 9223372036854775808u},
-      {"0xffffffffffffffff", true, std::numeric_limits<uint64_t>::max()},
-      {"0x10000000000000000", false, 0},
-      {"-0x7fffffffffffffff", false, 0},
-      {"-0x8000000000000000", false, 0},
-      {"-0x8000000000000001", false, 0},
-      {"0xFfffffffffffffff", true, std::numeric_limits<uint64_t>::max()},
-  };
+TEST(StringNumberConversion, StringToUnsignedLong) {
+  static_assert(
+      sizeof(long) == 4 || sizeof(long) == 8,
+      "Test not configured for " STRINGIFY(__SIZEOF_LONG__) "-byte long");
+  static constexpr auto kTestData = kTestDataFunc<unsigned long>();
 
-  for (size_t index = 0; index < base::size(kTestData); ++index) {
-    uint64_t value;
+  for (size_t index = 0; index < kTestData.size(); ++index) {
+    unsigned long value;
+    bool valid = StringToNumber(kTestData[index].string, &value);
+    if (kTestData[index].valid) {
+      EXPECT_TRUE(valid) << "index " << index << ", string "
+                         << kTestData[index].string;
+      if (valid) {
+        EXPECT_EQ(value, kTestData[index].value)
+            << "index " << index << ", string " << kTestData[index].string;
+      }
+    } else {
+      EXPECT_FALSE(valid) << "index " << index << ", string "
+                          << kTestData[index].string << ", value " << value;
+    }
+  }
+}
+
+TEST(StringNumberConversion, StringToLongLong) {
+  static_assert(sizeof(long long) == 8,
+                "Test only configured for 64-bit long long.");
+  static constexpr auto kTestData = kTestDataFunc<long long>();
+
+  for (size_t index = 0; index < kTestData.size(); ++index) {
+    long long value;
+    bool valid = StringToNumber(kTestData[index].string, &value);
+    if (kTestData[index].valid) {
+      EXPECT_TRUE(valid) << "index " << index << ", string "
+                         << kTestData[index].string;
+      if (valid) {
+        EXPECT_EQ(value, kTestData[index].value)
+            << "index " << index << ", string " << kTestData[index].string;
+      }
+    } else {
+      EXPECT_FALSE(valid) << "index " << index << ", string "
+                          << kTestData[index].string << ", value " << value;
+    }
+  }
+}
+
+TEST(StringNumberConversion, StringToUnsignedLongLong) {
+  static_assert(sizeof(unsigned long long) == 8,
+                "Test only configured for 64-bit unsigned long long.");
+  static constexpr auto kTestData = kTestDataFunc<unsigned long long>();
+
+  for (size_t index = 0; index < kTestData.size(); ++index) {
+    unsigned long long value;
     bool valid = StringToNumber(kTestData[index].string, &value);
     if (kTestData[index].valid) {
       EXPECT_TRUE(valid) << "index " << index << ", string "