diff --git a/source/filters/filter-shader.cpp b/source/filters/filter-shader.cpp
index 998bbe60..458acfda 100644
--- a/source/filters/filter-shader.cpp
+++ b/source/filters/filter-shader.cpp
@@ -217,11 +217,11 @@ void filter::shader::shader_instance::deactivate()
 
 bool filter::shader::shader_instance::valid_param(std::shared_ptr<gs::effect_parameter> param)
 {
-	if (strcmpi(param->get_name().c_str(), "ImageSource"))
+	if (strcmpi(param->get_name().c_str(), "ImageSource") == 0)
 		return false;
-	if (strcmpi(param->get_name().c_str(), "ImageSource_Size"))
+	if (strcmpi(param->get_name().c_str(), "ImageSource_Size") == 0)
 		return false;
-	if (strcmpi(param->get_name().c_str(), "ImageSource_Texel"))
+	if (strcmpi(param->get_name().c_str(), "ImageSource_Texel") == 0)
 		return false;
 	return true;
 }