diff --git a/src/gl/renderer/gl_renderbuffers.cpp b/src/gl/renderer/gl_renderbuffers.cpp
index 5fe2f5b3a8..f66ea1354e 100644
--- a/src/gl/renderer/gl_renderbuffers.cpp
+++ b/src/gl/renderer/gl_renderbuffers.cpp
@@ -55,14 +55,7 @@
 #include "doomerrors.h"
 
 CVAR(Int, gl_multisample, 1, CVAR_ARCHIVE|CVAR_GLOBALCONFIG);
-CUSTOM_CVAR(Bool, gl_renderbuffers, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
-{
-	// this CVAR alters some fixed colormap related settings
-	if (GLRenderer != nullptr && GLRenderer->mShaderManager != nullptr)
-	{
-		//GLRenderer->mShaderManager->ResetFixedColormap();
-	}
-}
+CVAR(Bool, gl_renderbuffers, true, CVAR_ARCHIVE | CVAR_GLOBALCONFIG | CVAR_NOINITCALL)
 
 //==========================================================================
 //
@@ -161,6 +154,7 @@ bool FGLRenderBuffers::Setup(int width, int height, int sceneWidth, int sceneHei
 		if (BuffersActive)
 			glBindFramebuffer(GL_FRAMEBUFFER, mOutputFB);
 		BuffersActive = gl_renderbuffers;
+		GLRenderer->mShaderManager->ResetFixedColormap();
 	}
 
 	if (!IsEnabled())