diff --git a/src/Nazara/Renderer/ShaderAst.cpp b/src/Nazara/Renderer/ShaderAst.cpp
index d60ebab6a..b6623cc48 100644
--- a/src/Nazara/Renderer/ShaderAst.cpp
+++ b/src/Nazara/Renderer/ShaderAst.cpp
@@ -122,12 +122,16 @@ namespace Nz::ShaderAst
 		switch (op)
 		{
 			case ShaderAst::BinaryType::Add:
-			case ShaderAst::BinaryType::Divide:
-			case ShaderAst::BinaryType::Multiply:
 			case ShaderAst::BinaryType::Substract:
 				exprType = left->GetExpressionType();
 				break;
 
+			case ShaderAst::BinaryType::Divide:
+			case ShaderAst::BinaryType::Multiply:
+				//FIXME
+				exprType = static_cast<ExpressionType>(std::max(UnderlyingCast(left->GetExpressionType()), UnderlyingCast(right->GetExpressionType())));
+				break;
+
 			case ShaderAst::BinaryType::Equality:
 				exprType = ExpressionType::Boolean;
 				break;
diff --git a/src/Nazara/Renderer/ShaderValidator.cpp b/src/Nazara/Renderer/ShaderValidator.cpp
index 2a4d38f25..c7a25989f 100644
--- a/src/Nazara/Renderer/ShaderValidator.cpp
+++ b/src/Nazara/Renderer/ShaderValidator.cpp
@@ -102,6 +102,14 @@ namespace Nz::ShaderAst
 			{
 				switch (leftType)
 				{
+					case ExpressionType::Float1:
+					{
+						if (Node::GetComponentType(rightType) != ExpressionType::Float1)
+							throw AstError{ "Left expression type is not compatible with right expression type" };
+
+						break;
+					}
+
 					case ExpressionType::Float2:
 					case ExpressionType::Float3:
 					case ExpressionType::Float4: