diff --git a/src/d_main.cpp b/src/d_main.cpp
index 869dce80b..23fd6eba7 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -2286,6 +2286,7 @@ void D_DoomMain (void)
 	const char *batchout = Args->CheckValue("-errorlog");
 	
 	C_InitConsole(80*8, 25*8, false);
+	I_DetectOS();
 
 	// +logfile gets checked too late to catch the full startup log in the logfile so do some extra check for it here.
 	FString logfile = Args->TakeValue("+logfile");
diff --git a/src/posix/cocoa/i_main.mm b/src/posix/cocoa/i_main.mm
index bcf1088a5..c873c1091 100644
--- a/src/posix/cocoa/i_main.mm
+++ b/src/posix/cocoa/i_main.mm
@@ -90,7 +90,7 @@ struct NSOperatingSystemVersion
 
 #endif // before 10.10
 
-static void I_DetectOS()
+void I_DetectOS()
 {
 	NSOperatingSystemVersion version = {};
 	NSProcessInfo* const processInfo = [NSProcessInfo processInfo];
@@ -172,7 +172,6 @@ void OriginalMainTry(int argc, char** argv)
 	progdir = [[exePath stringByDeletingLastPathComponent] UTF8String];
 	progdir += "/";
 
-	I_DetectOS();
 	D_DoomMain();
 }
 
diff --git a/src/posix/sdl/i_main.cpp b/src/posix/sdl/i_main.cpp
index 9de36729e..448215958 100644
--- a/src/posix/sdl/i_main.cpp
+++ b/src/posix/sdl/i_main.cpp
@@ -149,6 +149,11 @@ static int DoomSpecificInfo (char *buffer, char *end)
 	return p;
 }
 
+void I_DetectOS()
+{
+	// The POSIX version never implemented this.
+}
+
 void I_StartupJoysticks();
 void I_ShutdownJoysticks();
 
diff --git a/src/win32/i_main.cpp b/src/win32/i_main.cpp
index da686e53f..af9d63164 100644
--- a/src/win32/i_main.cpp
+++ b/src/win32/i_main.cpp
@@ -979,7 +979,6 @@ void DoMain (HINSTANCE hInstance)
 		CoInitialize (NULL);
 		atexit (UnCOM);
 		
-		I_DetectOS ();
 		D_DoomMain ();
 	}
 	catch (class CNoRunExit &)