diff --git a/CMakeLists.txt b/CMakeLists.txt
index d574b999c..95dba3dc3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -203,9 +203,9 @@ if( MSVC )
 	# Function-level linking
 	# Disable run-time type information
 	if ( HAVE_VULKAN )
-		set( ALL_C_FLAGS "/GF /Gy /permissive- /DHAVE_VULKAN /D_HAVE_SOFTPOLY" )
+		set( ALL_C_FLAGS "/GF /Gy /permissive- /DHAVE_VULKAN /DHAVE_SOFTPOLY" )
 	else()
-		set( ALL_C_FLAGS "/GF /Gy /permissive- /D_HAVE_SOFTPOLY" )
+		set( ALL_C_FLAGS "/GF /Gy /permissive- /DHAVE_SOFTPOLY" )
 	endif()
 
 	# Use SSE 2 as minimum always as the true color drawers needs it for __vectorcall
@@ -241,9 +241,9 @@ if( MSVC )
 else()
 	set( REL_LINKER_FLAGS "" )
 	if ( HAVE_VULKAN )
-		set( ALL_C_FLAGS "-ffp-contract=off -DHAVE_VULKAN -D_HAVE_SOFTPOLY" )
+		set( ALL_C_FLAGS "-ffp-contract=off -DHAVE_VULKAN -DHAVE_SOFTPOLY" )
 	else()
-		set( ALL_C_FLAGS "-ffp-contract=off -D_HAVE_SOFTPOLY" )
+		set( ALL_C_FLAGS "-ffp-contract=off -DHAVE_SOFTPOLY" )
 	endif()
 
 	if ( UNIX )
diff --git a/src/posix/sdl/sdlglvideo.cpp b/src/posix/sdl/sdlglvideo.cpp
index 6bf64b4db..66edd075e 100644
--- a/src/posix/sdl/sdlglvideo.cpp
+++ b/src/posix/sdl/sdlglvideo.cpp
@@ -259,7 +259,7 @@ bool I_CreateVulkanSurface(VkInstance instance, VkSurfaceKHR *surface)
 }
 #endif
 
-#if HAVE_SOFTPOLY
+#ifdef HAVE_SOFTPOLY
 namespace
 {
 	SDL_Renderer* polyrendertarget = nullptr;