diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 9a7cb6c5..3d948f7c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -286,7 +286,7 @@ jobs:
           set s=%H%\src
           cat .GITREV.txt
           set /p GITREV=<.GITREV.txt
-          cl -std:c++17 -Zc:__cplusplus -EHsc -J -O2 -W4 -WX -DUPX_VERSION_GITREV="""%GITREV%""" %DEFS% -I%H%\vendor -Feupx.exe %s%\*.cpp %s%\util\*.cpp %BDIR%\ucl\ucl.lib %BDIR%\zlib\zlib.lib /link setargv.obj
+          cl -std:c++17 -Zc:__cplusplus -EHsc -J -O2 -W4 -WX -DUPX_VERSION_GITREV="""%GITREV%""" %DEFS% -I%H%\vendor -I%H%\vendor\boost-pfr\include -Feupx.exe %s%\*.cpp %s%\util\*.cpp %BDIR%\ucl\ucl.lib %BDIR%\zlib\zlib.lib /link setargv.obj
       - name: 'Make artifact'
         shell: bash
         run: |
diff --git a/src/conf.h b/src/conf.h
index e78406c0..4fe9188f 100644
--- a/src/conf.h
+++ b/src/conf.h
@@ -743,8 +743,6 @@ struct upx_compress_result_t
 // globals
 **************************************************************************/
 
-#include "util/snprintf.h"   // must get included first!
-
 #include <exception>
 #include <new>
 #include <type_traits>
@@ -757,7 +755,11 @@ struct upx_compress_result_t
 #include <atomic>
 #define upx_std_atomic(Type)    std::atomic<Type>
 #endif
+#if WITH_BOOST_PFR
+#include <sstream>
+#endif
 
+#include "util/snprintf.h"   // must get included first!
 #include "options.h"
 #include "except.h"
 #include "bele.h"
@@ -775,37 +777,6 @@ unsigned membuffer_get_size(MemBuffer &mb);
 
 #include "util/xspan.h"
 
-//#define DOCTEST_CONFIG_DISABLE 1
-#include <doctest/doctest/parts/doctest_fwd.h>
-
-#if WITH_BOOST_PFR
-#include <boost/pfr/io.hpp>
-template <class A>
-__acc_noinline std::string pfr_str(const A &a) {
-    std::ostringstream ss;
-    ss << boost::pfr::io(a);
-    return ss.str();
-}
-template <class A, class B>
-__acc_noinline std::string pfr_str(const A &a, const B &b) {
-    std::ostringstream ss;
-    ss << boost::pfr::io(a);
-    ss << ' ';
-    ss << boost::pfr::io(b);
-    return ss.str();
-}
-template <class A, class B, class C>
-__acc_noinline std::string pfr_str(const A &a, const B &b, const C &c) {
-    std::ostringstream ss;
-    ss << boost::pfr::io(a);
-    ss << ' ';
-    ss << boost::pfr::io(b);
-    ss << ' ';
-    ss << boost::pfr::io(c);
-    return ss.str();
-}
-#endif // WITH_BOOST_PFR
-
 // util/dt_check.cpp
 void upx_compiler_sanity_check();
 int upx_doctest_check();
@@ -865,6 +836,57 @@ int upx_test_overlap       ( const upx_bytep buf,
                                    int method,
                              const upx_compress_result_t *cresult );
 
+
+/*************************************************************************
+//
+**************************************************************************/
+
+//#define DOCTEST_CONFIG_DISABLE 1
+#include <doctest/doctest/parts/doctest_fwd.h>
+
+#if WITH_BOOST_PFR
+#include <boost/pfr/io.hpp>
+template <class A>
+__acc_noinline std::string pfr_string(const A &a) {
+    std::ostringstream ss;
+    ss << boost::pfr::io(a);
+    return ss.str();
+}
+template <class A, class B>
+__acc_noinline std::string pfr_string(const A &a, const B &b) {
+    std::ostringstream ss;
+    ss << boost::pfr::io(a);
+    ss << ' ';
+    ss << boost::pfr::io(b);
+    return ss.str();
+}
+template <class A, class B, class C>
+__acc_noinline std::string pfr_string(const A &a, const B &b, const C &c) {
+    std::ostringstream ss;
+    ss << boost::pfr::io(a);
+    ss << ' ';
+    ss << boost::pfr::io(b);
+    ss << ' ';
+    ss << boost::pfr::io(c);
+    return ss.str();
+}
+template <class A, class B, class C, class D>
+__acc_noinline std::string pfr_string(const A &a, const B &b, const C &c, const D &d) {
+    std::ostringstream ss;
+    ss << boost::pfr::io(a);
+    ss << ' ';
+    ss << boost::pfr::io(b);
+    ss << ' ';
+    ss << boost::pfr::io(c);
+    ss << ' ';
+    ss << boost::pfr::io(d);
+    return ss.str();
+}
+// note: this MUST be a macro and not a function because of implicit temporary variable
+#define pfr_str(a,...)  (pfr_string(a, ##__VA_ARGS__).c_str())
+#endif // WITH_BOOST_PFR
+
+
 /*************************************************************************
 // raw_bytes() - get underlying memory from checked buffers/pointers.
 // This is overloaded by various utility classes like BoundedPtr,
diff --git a/src/util/dt_check.cpp b/src/util/dt_check.cpp
index ac31bb92..1fefbb9c 100644
--- a/src/util/dt_check.cpp
+++ b/src/util/dt_check.cpp
@@ -456,13 +456,13 @@ TEST_CASE("libc snprintf") {
 #if WITH_BOOST_PFR
 TEST_CASE("Boost.PFR") {
     int i = -1;
-    CHECK_EQ(strcmp(pfr_str(i).c_str(), "-1"), 0);
+    CHECK_EQ(strcmp(pfr_str(i), "-1"), 0);
     BE32 b32;
     b32 = 1;
     LE32 l32;
     l32 = 2;
-    CHECK_EQ(strcmp(pfr_str(b32).c_str(), "1"), 0);
-    CHECK_EQ(strcmp(pfr_str(l32).c_str(), "2"), 0);
+    CHECK_EQ(strcmp(pfr_str(b32), "1"), 0);
+    CHECK_EQ(strcmp(pfr_str(l32), "2"), 0);
     struct Foo {
         BE16 b16;
         BE32 b32;
@@ -478,7 +478,7 @@ TEST_CASE("Boost.PFR") {
     foo.l16 = 4;
     foo.l32 = 5;
     foo.l64 = 6;
-    CHECK_EQ(strcmp(pfr_str("foo", "=", foo).c_str(), "foo = {1, 2, 3, 4, 5, 6}"), 0);
+    CHECK_EQ(strcmp(pfr_str("foo", "=", foo), "foo = {1, 2, 3, 4, 5, 6}"), 0);
 }
 #endif // WITH_BOOST_PFR