diff --git a/BasiliskII/src/SDL/video_sdl.cpp b/BasiliskII/src/SDL/video_sdl.cpp
index 7fd3a832..5d142618 100644
--- a/BasiliskII/src/SDL/video_sdl.cpp
+++ b/BasiliskII/src/SDL/video_sdl.cpp
@@ -366,6 +366,7 @@ public:
 
 	virtual void switch_to_current_mode(void);
 	virtual void set_palette(uint8 *pal, int num);
+	virtual void set_gamma(uint8 *gamma, int num);
 
 	bool video_open(void);
 	void video_close(void);
@@ -1469,6 +1470,10 @@ void SDL_monitor_desc::set_palette(uint8 *pal, int num_in)
 	UNLOCK_PALETTE;
 }
 
+void SDL_monitor_desc::set_gamma(uint8 *gamma, int num_in)
+{
+	// Not implemented
+}
 
 /*
  *  Switch video mode
diff --git a/SheepShaver/src/Unix/configure.ac b/SheepShaver/src/Unix/configure.ac
index 8f22fe81..06d6b65e 100755
--- a/SheepShaver/src/Unix/configure.ac
+++ b/SheepShaver/src/Unix/configure.ac
@@ -72,7 +72,7 @@ AC_ARG_ENABLE(sdl-video,    [  --enable-sdl-video      use SDL for video graphic
 AC_ARG_ENABLE(sdl-audio,    [  --enable-sdl-audio      use SDL for audio [default=no]], [WANT_SDL_AUDIO=$enableval], [WANT_SDL_AUDIO=yes])
 AC_ARG_ENABLE(sdl-framework,    [  --enable-sdl-framework  use SDL framework [default=no]], [WANT_SDL_FRAMEWORK=$enableval], [WANT_SDL_FRAMEWORK=no])
 AC_ARG_ENABLE(sdl-framework-prefix,    [  --enable-sdl-framework-prefix=PFX    default=/Library/Frameworks], [SDL_FRAMEWORK="$enableval"], [SDL_FRAMEWORK=/Library/Frameworks])
-#AC_ARG_WITH(sdl1,            [  --with-sdl1             use SDL 1.x, rather than SDL 2.x [default=no]], [WANT_SDL_VERSION_MAJOR=1], [])
+AC_ARG_WITH(sdl1,            [  --with-sdl1             use SDL 1.x, rather than SDL 2.x [default=no]], [WANT_SDL_VERSION_MAJOR=1], [])
 
 dnl Checks for programs.
 AC_PROG_CC