diff --git a/CMakeLists.txt b/CMakeLists.txt
index 44c0e2aba..2c10ed16b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -124,8 +124,16 @@ if(USE_GCC_STYLE_LTCG)
 endif()
 
 if(MSVC)
-	# Disable non-standard conversion from string literal to (nonconst) char*
-	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zc:strictStrings")
+	if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
+		# Set up some additional flags only if we're using the MS compiler,
+		# and not the clang-based toolchain
+
+		# Disable non-standard conversion from string literal to (nonconst) char*
+		set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zc:strictStrings")
+
+		# Activate edit-and-continue
+		set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /ZI /Gy")
+	endif()
 
 	# Enable multi-core builds
 	set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /MP")
@@ -135,9 +143,6 @@ if(MSVC)
 	set(CMAKE_CXX_FLAGS_MINSIZEREL "${CMAKE_CXX_FLAGS_MINSIZEREL} /Ob2 /GL")
 	add_linker_flags(optimized MODULES exe shared static FLAGS "/LTCG:incremental")
 
-	# Activate edit-and-continue
-	set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} /ZI /Gy")
-
 	# do not link the release CRT in debug builds
 	set(CMAKE_EXE_LINKER_FLAGS_DEBUG "${CMAKE_EXE_LINKER_FLAGS_DEBUG} /NODEFAULTLIB:MSVCRT")
 	set(HAVE_PRECOMPILED_HEADERS ON CACHE INTERNAL "Compiler supports precompiled headers")
@@ -1301,7 +1306,7 @@ endif()
 # Precompiled header support for MSVC
 ############################################################################
 if(HAVE_PRECOMPILED_HEADERS)
-	if(MSVC)
+	if(CMAKE_CXX_COMPILER_ID MATCHES "MSVC")
 		get_property(OC_SOURCES TARGET openclonk PROPERTY SOURCES)
 		foreach(FILE ${OC_SOURCES})
 			get_filename_component(FILE_EXT ${FILE} EXT)
diff --git a/src/platform/C4WindowWin32.cpp b/src/platform/C4WindowWin32.cpp
index 6a4e203fe..8e44f85d8 100644
--- a/src/platform/C4WindowWin32.cpp
+++ b/src/platform/C4WindowWin32.cpp
@@ -1010,7 +1010,7 @@ bool C4AbstractApp::SetVideoMode(int iXRes, int iYRes, unsigned int iRefreshRate
 		dspMode.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
 		if (iRefreshRate != 0)
 			dspMode.dmFields |= DM_DISPLAYFREQUENCY;
-		DWORD rv = ChangeDisplaySettingsExW(iMonitor ? Mon.GetWideChar() : nullptr, &dspMode, nullptr, CDS_FULLSCREEN, nullptr);
+		LONG rv = ChangeDisplaySettingsExW(iMonitor ? Mon.GetWideChar() : nullptr, &dspMode, nullptr, CDS_FULLSCREEN, nullptr);
 		if (rv != DISP_CHANGE_SUCCESSFUL)
 		{
 			switch (rv)