diff --git a/src/libfuzzer_example_test.cc b/src/libfuzzer_example_test.cc
index 69d5da4..bbd77f7 100644
--- a/src/libfuzzer_example_test.cc
+++ b/src/libfuzzer_example_test.cc
@@ -15,7 +15,7 @@
 #include <stdlib.h>
 #include <sys/wait.h>
 
-#include <gtest/gtest.h>
+#include "gtest/gtest.h"
 
 const int kDefaultLibFuzzerError = 77;
 
diff --git a/src/libfuzzer_protobuf_mutator.cc b/src/libfuzzer_protobuf_mutator.cc
index 6b9ed9c..f998948 100644
--- a/src/libfuzzer_protobuf_mutator.cc
+++ b/src/libfuzzer_protobuf_mutator.cc
@@ -16,6 +16,7 @@
 
 #include <string.h>
 #include <cassert>
+#include <string>
 
 extern "C" size_t LLVMFuzzerMutate(uint8_t*, size_t, size_t);
 
diff --git a/src/libfuzzer_protobuf_mutator.h b/src/libfuzzer_protobuf_mutator.h
index 7857d1b..90f1f91 100644
--- a/src/libfuzzer_protobuf_mutator.h
+++ b/src/libfuzzer_protobuf_mutator.h
@@ -15,6 +15,8 @@
 #ifndef LIBFUZZER_PROTOBUF_MUTATOR_H_
 #define LIBFUZZER_PROTOBUF_MUTATOR_H_
 
+#include <string>
+
 #include "protobuf_mutator.h"
 
 namespace protobuf_mutator {
diff --git a/src/protobuf_mutator.cc b/src/protobuf_mutator.cc
index ae66fe6..7c6e43f 100644
--- a/src/protobuf_mutator.cc
+++ b/src/protobuf_mutator.cc
@@ -20,9 +20,8 @@
 #include <random>
 #include <string>
 
-#include "google/protobuf/message.h"
-
 #include "field_instance.h"
+#include "google/protobuf/message.h"
 #include "weighted_reservoir_sampler.h"
 
 using google::protobuf::Descriptor;
diff --git a/src/protobuf_mutator.h b/src/protobuf_mutator.h
index da02c29..69fa13d 100644
--- a/src/protobuf_mutator.h
+++ b/src/protobuf_mutator.h
@@ -20,6 +20,7 @@
 
 #include <memory>
 #include <random>
+#include <string>
 
 namespace google {
 namespace protobuf {
diff --git a/src/protobuf_mutator_test.cc b/src/protobuf_mutator_test.cc
index fe005bf..beeca6a 100644
--- a/src/protobuf_mutator_test.cc
+++ b/src/protobuf_mutator_test.cc
@@ -14,11 +14,15 @@
 
 #include "protobuf_mutator.h"
 
-#include <gtest/gtest.h>
+#include <algorithm>
+#include <set>
 #include <string>
+#include <utility>
+#include <vector>
 
 #include "google/protobuf/text_format.h"
 #include "google/protobuf/util/message_differencer.h"
+#include "gtest/gtest.h"
 
 #include "protobuf_mutator.pb.h"
 
diff --git a/src/weighted_reservoir_sampler_test.cc b/src/weighted_reservoir_sampler_test.cc
index e441ef8..956ee38 100644
--- a/src/weighted_reservoir_sampler_test.cc
+++ b/src/weighted_reservoir_sampler_test.cc
@@ -14,7 +14,10 @@
 
 #include "weighted_reservoir_sampler.h"
 
-#include <gtest/gtest.h>
+#include <tuple>
+#include <vector>
+
+#include "gtest/gtest.h"
 
 using testing::TestWithParam;
 using testing::ValuesIn;