diff --git a/.iwyu-mappings b/.iwyu-mappings
index 8830170..074f5b4 100644
--- a/.iwyu-mappings
+++ b/.iwyu-mappings
@@ -20,10 +20,5 @@
     { symbol: [ "std::reference_wrapper", "private", "<functional>", "public" ] },
     { symbol: [ "std::copy", "private", "<algorithm>", "public" ] },
     # Bug on fmtlib: format_error::~format_error is not from "format.h"
-    { include: [ "\"format.h\"", "private", "<slimlog/format.h>", "public" ] },
-    { include: [ "\"slimlog/format.h\"", "private", "<slimlog/format.h>", "public" ] },
-    { include: [ "\"slimlog/level.h\"", "private", "<slimlog/level.h>", "public" ] },
-    { include: [ "\"slimlog/record.h\"", "private", "<slimlog/record.h>", "public" ] },
-    { include: [ "\"slimlog/location.h\"", "private", "<slimlog/location.h>", "public" ] },
-    { include: [ "\"slimlog/policy.h\"", "private", "<slimlog/policy.h>", "public" ] },
+    { include: [ "\"format.h\"", "private", "\"slimlog/format.h\"", "public" ] },
 ]
diff --git a/include/slimlog/format-inl.h b/include/slimlog/format-inl.h
index 2b54be8..c413978 100644
--- a/include/slimlog/format-inl.h
+++ b/include/slimlog/format-inl.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/format.h>
+// IWYU pragma: private, include "slimlog/format.h"
 
-#include <slimlog/format.h> // IWYU pragma: associated
+#include "slimlog/format.h" // IWYU pragma: associated
 
 #ifdef SLIMLOG_FMTLIB
 #if __has_include(<fmt/base.h>)
diff --git a/include/slimlog/format.h b/include/slimlog/format.h
index 4cb7964..3074694 100644
--- a/include/slimlog/format.h
+++ b/include/slimlog/format.h
@@ -5,6 +5,10 @@
 
 #pragma once
 
+#include "slimlog/location.h"
+#include "slimlog/util/buffer.h"
+#include "slimlog/util/types.h"
+
 #ifdef SLIMLOG_FMTLIB
 #if __has_include(<fmt/base.h>)
 #include <fmt/base.h>
@@ -18,10 +22,6 @@
 #include <format>
 #endif
 
-#include <slimlog/location.h>
-#include <slimlog/util/buffer.h>
-#include <slimlog/util/types.h>
-
 #include <chrono>
 #include <concepts>
 #include <cstring>
@@ -367,5 +367,5 @@ struct std::formatter<SlimLog::FormatValue<T, Char>, Char> { // NOLINT(cert-dcl5
 #endif
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/format-inl.h> // IWYU pragma: keep
+#include "slimlog/format-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/logger.h b/include/slimlog/logger.h
index f9eefda..6e6fd0b 100644
--- a/include/slimlog/logger.h
+++ b/include/slimlog/logger.h
@@ -5,12 +5,12 @@
 
 #pragma once
 
-#include <slimlog/format.h>
-#include <slimlog/level.h>
-#include <slimlog/location.h>
-#include <slimlog/policy.h>
-#include <slimlog/sink.h>
-#include <slimlog/util/types.h>
+#include "slimlog/format.h"
+#include "slimlog/level.h"
+#include "slimlog/location.h"
+#include "slimlog/policy.h"
+#include "slimlog/sink.h"
+#include "slimlog/util/types.h"
 
 #include <cstddef>
 #include <memory>
diff --git a/include/slimlog/pattern-inl.h b/include/slimlog/pattern-inl.h
index dfd145a..a86c492 100644
--- a/include/slimlog/pattern-inl.h
+++ b/include/slimlog/pattern-inl.h
@@ -5,11 +5,11 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/pattern.h>
+// IWYU pragma: private, include "slimlog/pattern.h"
 
-#include <slimlog/pattern.h> // IWYU pragma: associated
-#include <slimlog/util/types.h>
-#include <slimlog/util/unicode.h>
+#include "slimlog/pattern.h" // IWYU pragma: associated
+#include "slimlog/util/types.h"
+#include "slimlog/util/unicode.h"
 
 #include <algorithm>
 #include <climits>
diff --git a/include/slimlog/pattern.h b/include/slimlog/pattern.h
index 84acc42..ddf41e9 100644
--- a/include/slimlog/pattern.h
+++ b/include/slimlog/pattern.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-#include <slimlog/format.h>
-#include <slimlog/level.h>
-#include <slimlog/record.h>
+#include "slimlog/format.h"
+#include "slimlog/level.h"
+#include "slimlog/record.h"
 
 #include <array>
 #include <chrono>
@@ -371,5 +371,5 @@ class Pattern {
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/pattern-inl.h> // IWYU pragma: keep
+#include "slimlog/pattern-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/record-inl.h b/include/slimlog/record-inl.h
index b5eb873..1b63025 100644
--- a/include/slimlog/record-inl.h
+++ b/include/slimlog/record-inl.h
@@ -5,10 +5,10 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/record.h>
+// IWYU pragma: private, include "slimlog/record.h"
 
-#include <slimlog/record.h> // IWYU pragma: associated
-#include <slimlog/util/unicode.h>
+#include "slimlog/record.h" // IWYU pragma: associated
+#include "slimlog/util/unicode.h"
 
 #include <utility>
 
diff --git a/include/slimlog/record.h b/include/slimlog/record.h
index 6da1e85..2160876 100644
--- a/include/slimlog/record.h
+++ b/include/slimlog/record.h
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <slimlog/level.h>
+#include "slimlog/level.h"
 
 #include <atomic>
 #include <chrono>
@@ -131,5 +131,5 @@ struct Record {
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/record-inl.h> // IWYU pragma: keep
+#include "slimlog/record-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/sink-inl.h b/include/slimlog/sink-inl.h
index f99ab01..04ad75b 100644
--- a/include/slimlog/sink-inl.h
+++ b/include/slimlog/sink-inl.h
@@ -5,14 +5,14 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/sink.h>
+// IWYU pragma: private, include "slimlog/sink.h"
 
 #ifndef SLIMLOG_HEADER_ONLY
-#include <slimlog/logger.h>
+#include "slimlog/logger.h"
 #endif
 
-#include <slimlog/sink.h> // IWYU pragma: associated
-#include <slimlog/util/os.h>
+#include "slimlog/sink.h" // IWYU pragma: associated
+#include "slimlog/util/os.h"
 
 #include <algorithm> // IWYU pragma: keep
 #include <iterator>
diff --git a/include/slimlog/sink.h b/include/slimlog/sink.h
index 600e764..7b3a8d2 100644
--- a/include/slimlog/sink.h
+++ b/include/slimlog/sink.h
@@ -5,13 +5,13 @@
 
 #pragma once
 
-#include <slimlog/format.h>
-#include <slimlog/level.h>
-#include <slimlog/location.h>
-#include <slimlog/pattern.h>
-#include <slimlog/policy.h>
-#include <slimlog/record.h>
-#include <slimlog/util/types.h>
+#include "slimlog/format.h"
+#include "slimlog/level.h"
+#include "slimlog/location.h"
+#include "slimlog/pattern.h"
+#include "slimlog/policy.h"
+#include "slimlog/record.h"
+#include "slimlog/util/types.h"
 
 #include <cstddef>
 #include <initializer_list>
@@ -403,5 +403,5 @@ class SinkDriver final {
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/sink-inl.h> // IWYU pragma: keep
+#include "slimlog/sink-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/sinks/file_sink-inl.h b/include/slimlog/sinks/file_sink-inl.h
index e420587..7662c3d 100644
--- a/include/slimlog/sinks/file_sink-inl.h
+++ b/include/slimlog/sinks/file_sink-inl.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/sinks/file_sink.h>
+// IWYU pragma: private, include "slimlog/sinks/file_sink.h"
 
-#include <slimlog/sinks/file_sink.h> // IWYU pragma: associated
+#include "slimlog/sinks/file_sink.h" // IWYU pragma: associated
 
 #if defined(_WIN32) && defined(__STDC_WANT_SECURE_LIB__)
 // In addition to <cstdio> below for fopen_s() on Windows
diff --git a/include/slimlog/sinks/file_sink.h b/include/slimlog/sinks/file_sink.h
index 0d855e6..f08aaae 100644
--- a/include/slimlog/sinks/file_sink.h
+++ b/include/slimlog/sinks/file_sink.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-#include <slimlog/logger.h>
-#include <slimlog/sink.h>
-#include <slimlog/util/types.h>
+#include "slimlog/logger.h"
+#include "slimlog/sink.h"
+#include "slimlog/util/types.h"
 
 #include <cstdio>
 #include <memory>
@@ -75,5 +75,5 @@ class FileSink : public FormattableSink<String, Char, BufferSize, Allocator> {
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/sinks/file_sink-inl.h> // IWYU pragma: keep
+#include "slimlog/sinks/file_sink-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/sinks/null_sink-inl.h b/include/slimlog/sinks/null_sink-inl.h
index 55384a2..792da61 100644
--- a/include/slimlog/sinks/null_sink-inl.h
+++ b/include/slimlog/sinks/null_sink-inl.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/sinks/null_sink.h>
+// IWYU pragma: private, include "slimlog/sinks/null_sink.h"
 
-#include <slimlog/sinks/null_sink.h> // IWYU pragma: associated
+#include "slimlog/sinks/null_sink.h" // IWYU pragma: associated
 
 namespace SlimLog {
 
diff --git a/include/slimlog/sinks/null_sink.h b/include/slimlog/sinks/null_sink.h
index 48aba44..cc6a305 100644
--- a/include/slimlog/sinks/null_sink.h
+++ b/include/slimlog/sinks/null_sink.h
@@ -5,8 +5,8 @@
 
 #pragma once
 
-#include <slimlog/sink.h>
-#include <slimlog/util/types.h>
+#include "slimlog/sink.h"
+#include "slimlog/util/types.h"
 
 #include <string_view>
 #include <utility>
@@ -55,5 +55,5 @@ class NullSink : public Sink<String, Char> {
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/sinks/null_sink-inl.h> // IWYU pragma: keep
+#include "slimlog/sinks/null_sink-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/sinks/ostream_sink-inl.h b/include/slimlog/sinks/ostream_sink-inl.h
index 839e9c7..d2096a5 100644
--- a/include/slimlog/sinks/ostream_sink-inl.h
+++ b/include/slimlog/sinks/ostream_sink-inl.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-// IWYU pragma: private, include <slimlog/sinks/ostream_sink.h>
+// IWYU pragma: private, include "slimlog/sinks/ostream_sink.h"
 
-#include <slimlog/sinks/ostream_sink.h> // IWYU pragma: associated
+#include "slimlog/sinks/ostream_sink.h" // IWYU pragma: associated
 
 namespace SlimLog {
 
diff --git a/include/slimlog/sinks/ostream_sink.h b/include/slimlog/sinks/ostream_sink.h
index c55c385..356e26c 100644
--- a/include/slimlog/sinks/ostream_sink.h
+++ b/include/slimlog/sinks/ostream_sink.h
@@ -5,9 +5,9 @@
 
 #pragma once
 
-#include <slimlog/logger.h>
-#include <slimlog/sink.h>
-#include <slimlog/util/types.h>
+#include "slimlog/logger.h"
+#include "slimlog/sink.h"
+#include "slimlog/util/types.h"
 
 #include <cstddef>
 #include <memory>
@@ -83,5 +83,5 @@ class OStreamSink : public FormattableSink<String, Char, BufferSize, Allocator>
 } // namespace SlimLog
 
 #ifdef SLIMLOG_HEADER_ONLY
-#include <slimlog/sinks/ostream_sink-inl.h> // IWYU pragma: keep
+#include "slimlog/sinks/ostream_sink-inl.h" // IWYU pragma: keep
 #endif
diff --git a/include/slimlog/util/buffer.h b/include/slimlog/util/buffer.h
index dae1334..7816f61 100644
--- a/include/slimlog/util/buffer.h
+++ b/include/slimlog/util/buffer.h
@@ -18,7 +18,7 @@
 #include <fmt/core.h>
 #endif
 #else
-#include <slimlog/util/types.h>
+#include "slimlog/util/types.h"
 
 #include <iterator>
 #endif
diff --git a/include/slimlog/util/unicode.h b/include/slimlog/util/unicode.h
index e2d3b5a..60731bc 100644
--- a/include/slimlog/util/unicode.h
+++ b/include/slimlog/util/unicode.h
@@ -5,7 +5,7 @@
 
 #pragma once
 
-#include <slimlog/util/types.h>
+#include "slimlog/util/types.h"
 
 #include <array>
 #include <cassert>
diff --git a/src/slimlog.cpp b/src/slimlog.cpp
index 303f290..4a9db0f 100644
--- a/src/slimlog.cpp
+++ b/src/slimlog.cpp
@@ -1,22 +1,22 @@
-#include <slimlog/format.h>
-#include <slimlog/logger.h>
-#include <slimlog/pattern.h>
-#include <slimlog/policy.h>
-#include <slimlog/record.h>
-#include <slimlog/sink.h>
-#include <slimlog/sinks/file_sink.h>
-#include <slimlog/sinks/null_sink.h>
-#include <slimlog/sinks/ostream_sink.h>
+#include "slimlog/format.h"
+#include "slimlog/logger.h"
+#include "slimlog/pattern.h"
+#include "slimlog/policy.h"
+#include "slimlog/record.h"
+#include "slimlog/sink.h"
+#include "slimlog/sinks/file_sink.h"
+#include "slimlog/sinks/null_sink.h"
+#include "slimlog/sinks/ostream_sink.h"
 
 #ifndef SLIMLOG_HEADER_ONLY
 // IWYU pragma: begin_keep
-#include <slimlog/format-inl.h>
-#include <slimlog/pattern-inl.h>
-#include <slimlog/record-inl.h>
-#include <slimlog/sink-inl.h>
-#include <slimlog/sinks/file_sink-inl.h>
-#include <slimlog/sinks/null_sink-inl.h>
-#include <slimlog/sinks/ostream_sink-inl.h>
+#include "slimlog/format-inl.h"
+#include "slimlog/pattern-inl.h"
+#include "slimlog/record-inl.h"
+#include "slimlog/sink-inl.h"
+#include "slimlog/sinks/file_sink-inl.h"
+#include "slimlog/sinks/null_sink-inl.h"
+#include "slimlog/sinks/ostream_sink-inl.h"
 // IWYU pragma: end_keep
 #endif