diff --git a/src/d_main.cpp b/src/d_main.cpp
index c6ef4727d..bbc5e8c86 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -2334,6 +2334,7 @@ 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 87d16095a..bf5c2ea75 100644
--- a/src/posix/cocoa/i_main.mm
+++ b/src/posix/cocoa/i_main.mm
@@ -76,7 +76,7 @@ void Mac_I_FatalError(const char* const message)
 }
 
 
-static void I_DetectOS()
+void I_DetectOS()
 {
 	SInt32 majorVersion = 0;
 	Gestalt(gestaltSystemVersionMajor, &majorVersion);
@@ -158,7 +158,6 @@ 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 e48786097..93ef90752 100644
--- a/src/posix/sdl/i_main.cpp
+++ b/src/posix/sdl/i_main.cpp
@@ -150,6 +150,11 @@ 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 619e73888..afd278139 100644
--- a/src/win32/i_main.cpp
+++ b/src/win32/i_main.cpp
@@ -999,7 +999,6 @@ void DoMain (HINSTANCE hInstance)
 		CoInitialize (NULL);
 		atexit (UnCOM);
 		
-		I_DetectOS ();
 		D_DoomMain ();
 	}
 	catch (class CNoRunExit &)