diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 9b50e6f5..f17e776a 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -28,15 +28,18 @@ include_directories(${OPENSSL_INCLUDE})
 
 if (CMAKE_SYSTEM MATCHES "Windows*")
     add_definitions (-DTARGET_WIN -D_SILENCE_STDEXT_HASH_DEPRECATION_WARNINGS -D_UNICODE -D_CRT_SECURE_NO_WARNINGS)
+    set (TARGET_WIN ON)
 endif()
 
 if (CMAKE_SYSTEM MATCHES "Linux*")
     add_definitions (-DTARGET_LINUX -DHAVE_NETINET_IN_H)
+    set (TARGET_LINUX ON)
 endif()
 
 
 if (CMAKE_SYSTEM MATCHES "Darwin*")
     add_definitions (-DTARGET_OSX)
+    set (TARGET_OSX ON)
 endif()
 
 if (CMAKE_SYSTEM MATCHES "Android")
@@ -45,10 +48,12 @@ if (CMAKE_SYSTEM MATCHES "Android")
     add_subdirectory (${OBOE_DIR} ./oboe)
     include_directories (${OBOE_DIR}/include)
     add_definitions(-DTARGET_ANDROID -DHAVE_NETINET_IN_H)
+    set (TARGET_ANDROID ON)
 endif()
 
 if (USE_MUSL)
     add_definitions(-DTARGET_MUSL)
+    set (TARGET_MUSL ON)
 endif()
 
 set (RTPHONE_SOURCES
diff --git a/src/engine/agent/Agent_AudioManager.cpp b/src/engine/agent/Agent_AudioManager.cpp
index 27d4cf79..2fd50bd0 100644
--- a/src/engine/agent/Agent_AudioManager.cpp
+++ b/src/engine/agent/Agent_AudioManager.cpp
@@ -6,6 +6,7 @@
 #include "Agent_AudioManager.h"
 #include "../engine/audio/Audio_WavFile.h"
 #include "../engine/audio/Audio_Null.h"
+#include "HL_String.h"
 
 #if defined(TARGET_ANDROID)
 # include "../engine/audio/Audio_Android.h"
@@ -171,7 +172,7 @@ void AudioManager::startPlayFile(int usageId, const std::string& path, AudioTarg
     // Check if file exists
     Audio::PWavFileReader r = std::make_shared<Audio::WavFileReader>();
 #ifdef TARGET_WIN
-    r->open(StringHelper::makeTstring(path));
+    r->open(strx::makeTstring(path));
 #else
     r->open(path);
 #endif
diff --git a/src/engine/audio/Audio_DirectSound.h b/src/engine/audio/Audio_DirectSound.h
index 2f394fe4..34e0c775 100644
--- a/src/engine/audio/Audio_DirectSound.h
+++ b/src/engine/audio/Audio_DirectSound.h
@@ -1,4 +1,4 @@
-/* Copyright(C) 2007-2017 VoIP objects (voipobjects.com)
+/* Copyright(C) 2007-2025 VoIP objects (voipobjects.com)
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
@@ -6,7 +6,7 @@
 #ifndef __AUDIO_DSOUND_H
 #define __AUDIO_DSOUND_H
 
-#include "../config.h"
+#include "../engine_config.h"
 
 #include <winsock2.h>
 #include <windows.h>
diff --git a/src/engine/audio/Audio_Null.cpp b/src/engine/audio/Audio_Null.cpp
index c2f8f102..40cc18d9 100644
--- a/src/engine/audio/Audio_Null.cpp
+++ b/src/engine/audio/Audio_Null.cpp
@@ -1,6 +1,7 @@
 #include "Audio_Null.h"
 #include "helper/HL_Log.h"
 #include <assert.h>
+#include <chrono>
 #define LOG_SUBSYSTEM "NULL audio"
 
 using namespace Audio;
diff --git a/src/engine/audio/Audio_Wmme.h b/src/engine/audio/Audio_Wmme.h
index c3e90c44..ba65f3bc 100644
--- a/src/engine/audio/Audio_Wmme.h
+++ b/src/engine/audio/Audio_Wmme.h
@@ -8,7 +8,7 @@
 
 #ifdef TARGET_WIN
 
-#include "../config.h"
+#include "../engine_config.h"
 
 #include <winsock2.h>
 #include <windows.h>
diff --git a/src/engine/helper/HL_String.cpp b/src/engine/helper/HL_String.cpp
index 60fada4e..429c6905 100644
--- a/src/engine/helper/HL_String.cpp
+++ b/src/engine/helper/HL_String.cpp
@@ -423,3 +423,26 @@ std::string strx::removeQuotes(const std::string& s)
 
     return r;
 }
+
+#if defined(TARGET_WIN)
+
+// MSVC++ lacks memmem support
+const void *memmem(const void *haystack, size_t haystack_len,
+                   const void * const needle, const size_t needle_len)
+{
+    if (haystack == NULL) return NULL; // or assert(haystack != NULL);
+    if (haystack_len == 0) return NULL;
+    if (needle == NULL) return NULL; // or assert(needle != NULL);
+    if (needle_len == 0) return NULL;
+
+    for (const char *h = (const char*)haystack;
+         haystack_len >= needle_len;
+         ++h, --haystack_len) {
+        if (!memcmp(h, needle, needle_len)) {
+            return h;
+        }
+    }
+    return nullptr;
+}
+#endif
+
diff --git a/src/engine/helper/HL_String.h b/src/engine/helper/HL_String.h
index 17126c30..550ef114 100644
--- a/src/engine/helper/HL_String.h
+++ b/src/engine/helper/HL_String.h
@@ -84,4 +84,11 @@ public:
 };
 
 
+#if defined(TARGET_WIN)
+
+// MSVC++ lacks memmem support
+extern const void *memmem(const void *haystack, size_t haystack_len,
+                          const void * const needle, const size_t needle_len);
+#endif
+
 #endif
diff --git a/src/engine/helper/HL_Sync.h b/src/engine/helper/HL_Sync.h
index 3fb85b71..9eebc00e 100644
--- a/src/engine/helper/HL_Sync.h
+++ b/src/engine/helper/HL_Sync.h
@@ -14,6 +14,11 @@
 #include <functional>
 #include <assert.h>
 
+#if defined(TARGET_WIN)
+# include <WinSock2.h>
+# include <Windows.h>
+#endif
+
 typedef std::recursive_mutex Mutex;
 typedef std::unique_lock<std::recursive_mutex> Lock;
 
diff --git a/src/engine/media/MT_AmrCodec.cpp b/src/engine/media/MT_AmrCodec.cpp
index cc32817e..d4eba761 100644
--- a/src/engine/media/MT_AmrCodec.cpp
+++ b/src/engine/media/MT_AmrCodec.cpp
@@ -6,6 +6,8 @@
 #include "../helper/HL_Log.h"
 #include "../helper/HL_IuUP.h"
 
+#include <iostream>
+
 #define LOG_SUBSYSTEM "AmrCodec"
 using namespace MT;
 
diff --git a/src/engine/media/MT_AudioReceiver.cpp b/src/engine/media/MT_AudioReceiver.cpp
index 7603c46d..ee891f1d 100644
--- a/src/engine/media/MT_AudioReceiver.cpp
+++ b/src/engine/media/MT_AudioReceiver.cpp
@@ -3,7 +3,9 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#define NOMINMAX
+#if defined(TARGET_WIN) && !defined(NOMINMAX)
+#  define NOMINMAX
+#endif
 
 #include "../engine_config.h"
 #include "MT_AudioReceiver.h"
@@ -14,6 +16,7 @@
 #include "../audio/Audio_Interface.h"
 #include "../audio/Audio_Resampler.h"
 #include <cmath>
+#include <iostream>
 
 #if !defined(TARGET_ANDROID) && !defined(TARGET_OPENWRT) && !defined(TARGET_WIN) && !defined(TARGET_RPI) && defined(USE_AMR_CODEC)
 # include "MT_AmrCodec.h"
diff --git a/src/libs/srtp/crypto/include/config.h b/src/libs/srtp/crypto/include/config.h
index 93c91148..2e85af68 100644
--- a/src/libs/srtp/crypto/include/config.h
+++ b/src/libs/srtp/crypto/include/config.h
@@ -3,10 +3,6 @@
 
 #define HAVE_STDLIB_H
 
-#ifdef WIN32
-# define inline __inline
-#endif
-
 #ifdef WIN32
 #define HAVE_WINSOCK2_H   1
 #define CPU_CISC 1