diff --git a/libc/test/src/stdio/fgetc_test.cpp b/libc/test/src/stdio/fgetc_test.cpp
index 7c652f666a8f3..b2e5cc028146b 100644
--- a/libc/test/src/stdio/fgetc_test.cpp
+++ b/libc/test/src/stdio/fgetc_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/libc_errno.h"
 #include "src/stdio/clearerr.h"
 #include "src/stdio/fclose.h"
 #include "src/stdio/feof.h"
@@ -33,6 +34,7 @@ class LlvmLibcGetcTest : public LIBC_NAMESPACE::testing::ErrnoCheckingTest {
     // This is an error and not a real EOF.
     ASSERT_EQ(LIBC_NAMESPACE::feof(file), 0);
     ASSERT_NE(LIBC_NAMESPACE::ferror(file), 0);
+    libc_errno = 0;
 
     ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file));
 
diff --git a/libc/test/src/stdio/fgetc_unlocked_test.cpp b/libc/test/src/stdio/fgetc_unlocked_test.cpp
index f4471dd82df15..d74ff9572224b 100644
--- a/libc/test/src/stdio/fgetc_unlocked_test.cpp
+++ b/libc/test/src/stdio/fgetc_unlocked_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/libc_errno.h"
 #include "src/stdio/fclose.h"
 #include "src/stdio/feof.h"
 #include "src/stdio/feof_unlocked.h"
@@ -36,6 +37,7 @@ class LlvmLibcGetcTest : public LIBC_NAMESPACE::testing::ErrnoCheckingTest {
     // This is an error and not a real EOF.
     ASSERT_EQ(LIBC_NAMESPACE::feof(file), 0);
     ASSERT_NE(LIBC_NAMESPACE::ferror(file), 0);
+    libc_errno = 0;
 
     ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file));
 
diff --git a/libc/test/src/stdio/fgets_test.cpp b/libc/test/src/stdio/fgets_test.cpp
index c00a9256af52d..acfd6fa34b7e3 100644
--- a/libc/test/src/stdio/fgets_test.cpp
+++ b/libc/test/src/stdio/fgets_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "src/__support/libc_errno.h"
 #include "src/stdio/fclose.h"
 #include "src/stdio/feof.h"
 #include "src/stdio/ferror.h"
@@ -36,6 +37,7 @@ TEST_F(LlvmLibcFgetsTest, WriteAndReadCharacters) {
   // This is an error and not a real EOF.
   ASSERT_EQ(LIBC_NAMESPACE::feof(file), 0);
   ASSERT_NE(LIBC_NAMESPACE::ferror(file), 0);
+  libc_errno = 0;
 
   ASSERT_EQ(0, LIBC_NAMESPACE::fclose(file));
 
diff --git a/libc/test/src/stdio/setvbuf_test.cpp b/libc/test/src/stdio/setvbuf_test.cpp
index 4144bc1bef447..a0936ba79ef73 100644
--- a/libc/test/src/stdio/setvbuf_test.cpp
+++ b/libc/test/src/stdio/setvbuf_test.cpp
@@ -11,6 +11,7 @@
 #include "src/stdio/fread.h"
 #include "src/stdio/fwrite.h"
 #include "src/stdio/setvbuf.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
 #include "test/UnitTest/Test.h"
 
 #include "hdr/stdio_macros.h"