diff --git a/libs/gfx/include/psemek/gfx/program.hpp b/libs/gfx/include/psemek/gfx/program.hpp
index 3a63361d..dcd047cb 100644
--- a/libs/gfx/include/psemek/gfx/program.hpp
+++ b/libs/gfx/include/psemek/gfx/program.hpp
@@ -34,6 +34,7 @@ namespace psemek::gfx
 
 			GLint location() const { return location_; }
 
+			void operator = (bool b);
 			void operator = (int i);
 			void operator = (unsigned int i);
 			void operator = (float f);
diff --git a/libs/gfx/source/program.cpp b/libs/gfx/source/program.cpp
index e96c7fab..a610f957 100644
--- a/libs/gfx/source/program.cpp
+++ b/libs/gfx/source/program.cpp
@@ -9,6 +9,11 @@
 namespace psemek::gfx
 {
 
+	void program::uniform_proxy::operator = (bool b)
+	{
+		gl::Uniform1i(location_, b ? 1 : 0);
+	}
+
 	void program::uniform_proxy::operator = (int i)
 	{
 		gl::Uniform1i(location_, i);