diff --git a/CHANGES.md b/CHANGES.md
index 36da263117..7a83c3f2b7 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -11,7 +11,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 
 ## [Unreleased]
 ### Added
-* `FileSignature.Promised` and `JarState.Promised` to facilitate round-trip serialization for the Gradle configuration cache. ([#1945](https://github.com/diffplug/spotless/pull/1945)) 
+* `FileSignature.Promised` and `JarState.Promised` to facilitate round-trip serialization for the Gradle configuration cache. ([#1945](https://github.com/diffplug/spotless/pull/1945))
 * Respect `.editorconfig` settings for formatting shell via `shfmt` ([#2031](https://github.com/diffplug/spotless/pull/2031))
 ### Fixed
 * Check if ktlint_code_style is set in .editorconfig before overriding it ([#2143](https://github.com/diffplug/spotless/issues/2143))
@@ -19,6 +19,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Correctly provide EditorConfig property types for Ktlint ([#2052](https://github.com/diffplug/spotless/issues/2052))
 * Made ShadowCopy (`npmInstallCache`) more robust by re-creating the cache dir if it goes missing ([#1984](https://github.com/diffplug/spotless/issues/1984),[2096](https://github.com/diffplug/spotless/pull/2096))
 * scalafmt.conf fileOverride section now works correctly ([#1854](https://github.com/diffplug/spotless/pull/1854))
+* Fix stdin pipe is being closed exception on Windows for large .proto files ([#2147](https://github.com/diffplug/spotless/issues/2147))
 * Reworked ShadowCopy (`npmInstallCache`) to use atomic filesystem operations, resolving several race conditions that could arise ([#2151](https://github.com/diffplug/spotless/pull/2151))
 ### Changes
 * Bump default `cleanthat` version to latest `2.16` -> `2.20`. ([#1725](https://github.com/diffplug/spotless/pull/1725))
diff --git a/lib/src/main/java/com/diffplug/spotless/ProcessRunner.java b/lib/src/main/java/com/diffplug/spotless/ProcessRunner.java
index 48307d7d3a..e7755f75bd 100644
--- a/lib/src/main/java/com/diffplug/spotless/ProcessRunner.java
+++ b/lib/src/main/java/com/diffplug/spotless/ProcessRunner.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2020-2023 DiffPlug
+ * Copyright 2020-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -163,6 +163,7 @@ public LongRunningProcess start(@Nullable File cwd, @Nullable Map<String, String
 		}
 		// write stdin
 		process.getOutputStream().write(stdin);
+		process.getOutputStream().flush();
 		process.getOutputStream().close();
 		return new LongRunningProcess(process, args, outputFut, errorFut);
 	}
diff --git a/plugin-gradle/CHANGES.md b/plugin-gradle/CHANGES.md
index 280b870e7f..42b6392975 100644
--- a/plugin-gradle/CHANGES.md
+++ b/plugin-gradle/CHANGES.md
@@ -5,7 +5,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 ## [Unreleased]
 ### Added
 * Full, no-asterisk support of Gradle configuration cache. ([#1274](https://github.com/diffplug/spotless/issues/1274), giving up on [#987](https://github.com/diffplug/spotless/issues/987))
-  * In order to use `custom`, you must now use Gradle 8.0+. 
+  * In order to use `custom`, you must now use Gradle 8.0+.
 * Respect `.editorconfig` settings for formatting shell via `shfmt` ([#2031](https://github.com/diffplug/spotless/pull/2031))
 * Add support for formatting and sorting Maven POMs ([#2082](https://github.com/diffplug/spotless/issues/2082))
 ### Fixed
@@ -16,6 +16,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Fixed memory leak introduced in 6.21.0 ([#2067](https://github.com/diffplug/spotless/issues/2067))
 * Made ShadowCopy (`npmInstallCache`) more robust by re-creating the cache dir if it goes missing ([#1984](https://github.com/diffplug/spotless/issues/1984),[2096](https://github.com/diffplug/spotless/pull/2096))
 * scalafmt.conf fileOverride section now works correctly ([#1854](https://github.com/diffplug/spotless/pull/1854))
+* Fix stdin pipe is being closed exception on Windows for large .proto files ([#2147](https://github.com/diffplug/spotless/issues/2147))
 * Reworked ShadowCopy (`npmInstallCache`) to use atomic filesystem operations, resolving several race conditions that could arise ([#2151](https://github.com/diffplug/spotless/pull/2151))
 ### Changes
 * Bump default `cleanthat` version to latest `2.16` -> `2.20`. ([#1725](https://github.com/diffplug/spotless/pull/1725))
diff --git a/plugin-gradle/src/test/java/com/diffplug/gradle/spotless/BufIntegrationTest.java b/plugin-gradle/src/test/java/com/diffplug/gradle/spotless/BufIntegrationTest.java
index b91512c7ed..be26cc8e71 100644
--- a/plugin-gradle/src/test/java/com/diffplug/gradle/spotless/BufIntegrationTest.java
+++ b/plugin-gradle/src/test/java/com/diffplug/gradle/spotless/BufIntegrationTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2022-2023 DiffPlug
+ * Copyright 2022-2024 DiffPlug
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,22 @@
 
 @BufTest
 class BufIntegrationTest extends GradleIntegrationHarness {
+	@Test
+	void bufLarge() throws IOException {
+		setFile("build.gradle").toLines(
+				"plugins {",
+				"  id 'com.diffplug.spotless'",
+				"}",
+				"spotless {",
+				"  protobuf {",
+				"    buf()",
+				"  }",
+				"}");
+		setFile("buf.proto").toResource("protobuf/buf/buf_large.proto");
+		gradleRunner().withArguments("spotlessApply").build();
+		assertFile("buf.proto").sameAsResource("protobuf/buf/buf_large.proto.clean");
+	}
+
 	@Test
 	void buf() throws IOException {
 		setFile("build.gradle").toLines(
diff --git a/plugin-maven/CHANGES.md b/plugin-maven/CHANGES.md
index 1646481d41..50fd82e9b6 100644
--- a/plugin-maven/CHANGES.md
+++ b/plugin-maven/CHANGES.md
@@ -13,6 +13,7 @@ We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (
 * Correctly provide EditorConfig property types for Ktlint ([#2052](https://github.com/diffplug/spotless/issues/2052))
 * Made ShadowCopy (`npmInstallCache`) more robust by re-creating the cache dir if it goes missing ([#1984](https://github.com/diffplug/spotless/issues/1984),[2096](https://github.com/diffplug/spotless/pull/2096))
 * scalafmt.conf fileOverride section now works correctly ([#1854](https://github.com/diffplug/spotless/pull/1854))
+* Fix stdin pipe is being closed exception on Windows for large .proto files ([#2147](https://github.com/diffplug/spotless/issues/2147))
 * Reworked ShadowCopy (`npmInstallCache`) to use atomic filesystem operations, resolving several race conditions that could arise ([#2151](https://github.com/diffplug/spotless/pull/2151))
 ### Changes
 * Bump default `cleanthat` version to latest `2.16` -> `2.20`. ([#1725](https://github.com/diffplug/spotless/pull/1725))
diff --git a/testlib/src/main/resources/protobuf/buf/buf_large.proto b/testlib/src/main/resources/protobuf/buf/buf_large.proto
new file mode 100644
index 0000000000..01a638d726
--- /dev/null
+++ b/testlib/src/main/resources/protobuf/buf/buf_large.proto
@@ -0,0 +1,229 @@
+syntax = "proto3";
+
+package com.diffplug.gradle.spotless.buf.proto;
+
+option java_multiple_files = true;
+
+message Message {
+  string message = 1;
+}
+
+service Services {
+rpc Echo(Message) returns (Message);
+}
+
+message Message01 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message02 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message03 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message04 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message05 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message06 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message07 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message08 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message09 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message10 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message11 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message12 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message13 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message14 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message15 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message16 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message17 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message18 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+string message9 = 9;
+}
diff --git a/testlib/src/main/resources/protobuf/buf/buf_large.proto.clean b/testlib/src/main/resources/protobuf/buf/buf_large.proto.clean
new file mode 100644
index 0000000000..c4218adfc8
--- /dev/null
+++ b/testlib/src/main/resources/protobuf/buf/buf_large.proto.clean
@@ -0,0 +1,229 @@
+syntax = "proto3";
+
+package com.diffplug.gradle.spotless.buf.proto;
+
+option java_multiple_files = true;
+
+message Message {
+  string message = 1;
+}
+
+service Services {
+  rpc Echo(Message) returns (Message);
+}
+
+message Message01 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message02 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message03 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message04 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message05 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message06 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message07 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message08 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message09 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message10 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message11 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message12 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message13 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message14 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message15 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message16 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message17 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}
+
+message Message18 {
+  string message1 = 1;
+  string message2 = 2;
+  string message3 = 3;
+  string message4 = 4;
+  string message5 = 5;
+  string message6 = 6;
+  string message7 = 7;
+  string message8 = 8;
+  string message9 = 9;
+}