diff --git a/libc/test/src/__support/CMakeLists.txt b/libc/test/src/__support/CMakeLists.txt
index fa35aa45712ff..a8c5517238882 100644
--- a/libc/test/src/__support/CMakeLists.txt
+++ b/libc/test/src/__support/CMakeLists.txt
@@ -40,6 +40,7 @@ add_libc_unittest(
   DEPENDS
     libc.src.__support.str_to_float
     libc.src.__support.uint128
+    libc.src.errno.errno
 )
 
 add_libc_unittest(
diff --git a/libc/test/src/__support/str_to_float_test.cpp b/libc/test/src/__support/str_to_float_test.cpp
index b5bb3b931a8af..4ebdb33549ef6 100644
--- a/libc/test/src/__support/str_to_float_test.cpp
+++ b/libc/test/src/__support/str_to_float_test.cpp
@@ -9,6 +9,7 @@
 #include "src/__support/FPUtil/FPBits.h"
 #include "src/__support/UInt128.h"
 #include "src/__support/str_to_float.h"
+#include "src/errno/libc_errno.h"
 
 #include "test/UnitTest/Test.h"
 
@@ -78,7 +79,7 @@ class LlvmLibcStrToFloatTest : public __llvm_libc::testing::Test {
     typename __llvm_libc::fputil::FPBits<T>::UIntType actual_output_mantissa =
         0;
     uint32_t actual_output_exp2 = 0;
-    errno = 0;
+    libc_errno = 0;
 
     auto result = __llvm_libc::internal::simple_decimal_conversion<T>(numStart);
 
@@ -250,7 +251,7 @@ TEST(LlvmLibcStrToFloatTest, SimpleDecimalConversionExtraTypes) {
   uint32_t float_output_mantissa = 0;
   uint32_t output_exp2 = 0;
 
-  errno = 0;
+  libc_errno = 0;
   auto float_result = __llvm_libc::internal::simple_decimal_conversion<float>(
       "123456789012345678900");
   float_output_mantissa = float_result.num.mantissa;
@@ -262,7 +263,7 @@ TEST(LlvmLibcStrToFloatTest, SimpleDecimalConversionExtraTypes) {
   uint64_t double_output_mantissa = 0;
   output_exp2 = 0;
 
-  errno = 0;
+  libc_errno = 0;
   auto double_result = __llvm_libc::internal::simple_decimal_conversion<double>(
       "123456789012345678900");
 
diff --git a/libc/test/src/errno/errno_test.cpp b/libc/test/src/errno/errno_test.cpp
index 86a9a88e86685..33185c2bcf6f5 100644
--- a/libc/test/src/errno/errno_test.cpp
+++ b/libc/test/src/errno/errno_test.cpp
@@ -6,11 +6,11 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "src/errno/llvmlibc_errno.h"
+#include "src/errno/libc_errno.h"
 #include "test/UnitTest/Test.h"
 
 TEST(LlvmLibcErrnoTest, Basic) {
   int test_val = 123;
-  llvmlibc_errno = test_val;
-  ASSERT_EQ(test_val, llvmlibc_errno);
+  libc_errno = test_val;
+  ASSERT_EQ(test_val, libc_errno);
 }
diff --git a/libc/test/src/string/CMakeLists.txt b/libc/test/src/string/CMakeLists.txt
index c9623a330b1c2..67f49ab3a114f 100644
--- a/libc/test/src/string/CMakeLists.txt
+++ b/libc/test/src/string/CMakeLists.txt
@@ -161,7 +161,6 @@ add_libc_unittest(
   SRCS
     strdup_test.cpp
   DEPENDS
-    libc.include.errno
     libc.include.stdlib
     libc.src.string.strdup
     libc.src.errno.errno
diff --git a/libc/test/src/string/strdup_test.cpp b/libc/test/src/string/strdup_test.cpp
index ffbc55a70fb21..ee46882233dd3 100644
--- a/libc/test/src/string/strdup_test.cpp
+++ b/libc/test/src/string/strdup_test.cpp
@@ -6,18 +6,18 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/errno/libc_errno.h"
 #include "src/string/strdup.h"
 #include "test/UnitTest/Test.h"
 
-#include <errno.h>
 #include <stdlib.h>
 
 TEST(LlvmLibcStrDupTest, EmptyString) {
   const char *empty = "";
 
-  errno = 0;
+  libc_errno = 0;
   char *result = __llvm_libc::strdup(empty);
-  ASSERT_EQ(errno, 0);
+  ASSERT_EQ(libc_errno, 0);
 
   ASSERT_NE(result, static_cast<char *>(nullptr));
   ASSERT_NE(empty, const_cast<const char *>(result));
@@ -28,9 +28,9 @@ TEST(LlvmLibcStrDupTest, EmptyString) {
 TEST(LlvmLibcStrDupTest, AnyString) {
   const char *abc = "abc";
 
-  errno = 0;
+  libc_errno = 0;
   char *result = __llvm_libc::strdup(abc);
-  ASSERT_EQ(errno, 0);
+  ASSERT_EQ(libc_errno, 0);
 
   ASSERT_NE(result, static_cast<char *>(nullptr));
   ASSERT_NE(abc, const_cast<const char *>(result));
@@ -39,9 +39,9 @@ TEST(LlvmLibcStrDupTest, AnyString) {
 }
 
 TEST(LlvmLibcStrDupTest, NullPtr) {
-  errno = 0;
+  libc_errno = 0;
   char *result = __llvm_libc::strdup(nullptr);
-  ASSERT_EQ(errno, 0);
+  ASSERT_EQ(libc_errno, 0);
 
   ASSERT_EQ(result, static_cast<char *>(nullptr));
 }