diff --git a/GPU/Common/PostShader.cpp b/GPU/Common/PostShader.cpp
index 636c1b39e8..0cf1971e53 100644
--- a/GPU/Common/PostShader.cpp
+++ b/GPU/Common/PostShader.cpp
@@ -250,6 +250,16 @@ void ReloadAllPostShaderInfo(Draw::DrawContext *draw) {
 	LoadPostShaderInfo(draw, directories);
 }
 
+void RemoveUnknownPostShaders(std::vector<std::string> *names) {
+	for (auto iter = names->begin(); iter != names->end(); ) {
+		if (GetPostShaderInfo(*iter) == nullptr) {
+			iter = names->erase(iter);
+		} else {
+			++iter;
+		}
+	}
+}
+
 const ShaderInfo *GetPostShaderInfo(const std::string &name) {
 	for (size_t i = 0; i < shaderInfo.size(); i++) {
 		if (shaderInfo[i].section == name)
diff --git a/GPU/Common/PostShader.h b/GPU/Common/PostShader.h
index 06fc69a159..4b4061988c 100644
--- a/GPU/Common/PostShader.h
+++ b/GPU/Common/PostShader.h
@@ -114,3 +114,4 @@ const std::vector<ShaderInfo> &GetAllPostShaderInfo();
 
 const TextureShaderInfo *GetTextureShaderInfo(const std::string &name);
 const std::vector<TextureShaderInfo> &GetAllTextureShaderInfo();
+void RemoveUnknownPostShaders(std::vector<std::string> *names);
diff --git a/GPU/Common/PresentationCommon.cpp b/GPU/Common/PresentationCommon.cpp
index e07eec1499..f8837e2808 100644
--- a/GPU/Common/PresentationCommon.cpp
+++ b/GPU/Common/PresentationCommon.cpp
@@ -879,6 +879,7 @@ void PresentationCommon::CalculateRenderResolution(int *width, int *height, int
 	std::vector<const ShaderInfo *> shaderInfo;
 	if (!g_Config.vPostShaderNames.empty()) {
 		ReloadAllPostShaderInfo(draw_);
+		RemoveUnknownPostShaders(&g_Config.vPostShaderNames);
 		shaderInfo = GetFullPostShadersChain(g_Config.vPostShaderNames);
 	}
 
diff --git a/assets/shaders/defaultshaders.ini b/assets/shaders/defaultshaders.ini
index 2a33454069..b6412bb357 100644
--- a/assets/shaders/defaultshaders.ini
+++ b/assets/shaders/defaultshaders.ini
@@ -28,11 +28,6 @@ Name=Vignette
 Author=Henrik
 Fragment=vignette.fsh
 Vertex=fxaa.vsh
-[Grayscale]
-Name=Grayscale
-Author=Henrik
-Fragment=grayscale.fsh
-Vertex=fxaa.vsh
 [Bloom]
 Name=Bloom
 Fragment=bloom.fsh
diff --git a/assets/shaders/grayscale.fsh b/assets/shaders/grayscale.fsh
deleted file mode 100644
index f309204e12..0000000000
--- a/assets/shaders/grayscale.fsh
+++ /dev/null
@@ -1,16 +0,0 @@
-// Simple grayscale shader
-
-#ifdef GL_ES
-precision mediump float;
-precision mediump int;
-#endif
-
-uniform sampler2D sampler0;
-varying vec2 v_texcoord0;
-
-void main() {
-  vec3 rgb = texture2D(sampler0, v_texcoord0.xy).xyz;
-  float luma = dot(rgb, vec3(0.299, 0.587, 0.114));
-  gl_FragColor.rgb = vec3(luma, luma, luma);
-  gl_FragColor.a = 1.0;
-}