diff --git a/unittests/Basic/URI.cpp b/unittests/Basic/URI.cpp
index 4a1fc148..344889fa 100644
--- a/unittests/Basic/URI.cpp
+++ b/unittests/Basic/URI.cpp
@@ -1,9 +1,9 @@
 #include <gtest/gtest.h>
 #include <Basic/URI.h>
 
-namespace {
+namespace clice {
 
-using namespace clice;
+namespace {
 
 TEST(URITest, ConstructorAndAccessors) {
     URI uri("https", "reviews.llvm.org", "/D41946");
@@ -43,3 +43,5 @@ TEST(URITest, ParseFunction) {
 
 }  // namespace
 
+}  // namespace clice
+
diff --git a/unittests/Compiler/Compiler.cpp b/unittests/Compiler/Compiler.cpp
index 7d9cbfd0..0a8a198b 100644
--- a/unittests/Compiler/Compiler.cpp
+++ b/unittests/Compiler/Compiler.cpp
@@ -2,9 +2,9 @@
 #include "Compiler/Compiler.h"
 #include <Support/FileSystem.h>
 
-namespace {
+namespace clice {
 
-using namespace clice;
+namespace {
 
 TEST(Compiler, buildAST) {
     const char* code = R"cpp(
@@ -223,3 +223,6 @@ export int foo = 1;
 }
 
 }  // namespace
+
+}  // namespace clice
+
diff --git a/unittests/Compiler/Resolver.cpp b/unittests/Compiler/Resolver.cpp
index cee95c1f..0e9d95f3 100644
--- a/unittests/Compiler/Resolver.cpp
+++ b/unittests/Compiler/Resolver.cpp
@@ -2,12 +2,10 @@
 #include <Compiler/Compiler.h>
 #include <Compiler/Resolver.h>
 
+namespace clice {
+
 namespace {
 
-using namespace clice;
-
-namespace testing {}  // namespace testing
-
 struct TemplateResolverTester : public clang::RecursiveASTVisitor<TemplateResolverTester> {
     TemplateResolverTester(llvm::StringRef code) {
         compileArgs = {
@@ -485,3 +483,5 @@ struct test {
 
 }  // namespace
 
+}  // namespace clice
+
diff --git a/unittests/Feature/CodeCompletion.cpp b/unittests/Feature/CodeCompletion.cpp
index 2ca48f82..ef4150c1 100644
--- a/unittests/Feature/CodeCompletion.cpp
+++ b/unittests/Feature/CodeCompletion.cpp
@@ -1,12 +1,9 @@
 #include "../Test.h"
-#include "Compiler/Compiler.h"
-#include "Support/Support.h"
-
 #include "Feature/CodeCompletion.h"
 
-namespace {
+namespace clice {
 
-using namespace clice;
+namespace {
 
 TEST(Feature, CodeCompletion) {
     const char* code = R"cpp(
@@ -41,3 +38,6 @@ int main() {
 }
 
 }  // namespace
+
+}  // namespace clice
+
diff --git a/unittests/Server/Async.cpp b/unittests/Server/Async.cpp
index 12aa8dad..aa94e130 100644
--- a/unittests/Server/Async.cpp
+++ b/unittests/Server/Async.cpp
@@ -1,9 +1,9 @@
 #include "../Test.h"
 #include "Server/Async.h"
 
-namespace {
+namespace clice {
 
-using namespace clice;
+namespace {
 
 async::promise<int> add(int a, int b) {
     co_return a + b;
@@ -23,3 +23,6 @@ TEST(clice, coroutine) {
 }
 
 }  // namespace
+
+}  // namespace clice
+
diff --git a/unittests/Support/JSON.cpp b/unittests/Support/JSON.cpp
index a3ffe883..b020aac9 100644
--- a/unittests/Support/JSON.cpp
+++ b/unittests/Support/JSON.cpp
@@ -38,11 +38,11 @@ TEST(Support, JSON) {
         {"y", 2},
     };
 
-    auto point = clice::json::deserialize<Point>(std::move(object));
+    auto point = json::deserialize<Point>(std::move(object));
     ASSERT_EQ(point.x, 1);
     ASSERT_EQ(point.y, 2);
 
-    auto result = clice::json::serialize(point);
+    auto result = json::serialize(point);
     ASSERT_EQ(result, object);
 }