diff --git a/internal/shader/expr.go b/internal/shader/expr.go
index d79ea28b6..971760ba5 100644
--- a/internal/shader/expr.go
+++ b/internal/shader/expr.go
@@ -379,34 +379,58 @@ func (cs *compileState) parseExpr(block *block, expr ast.Expr, markLocalVariable
 			var t shaderir.Type
 			switch callee.BuiltinFunc {
 			case shaderir.BoolF:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Bool}
 			case shaderir.IntF:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Int}
 			case shaderir.FloatF:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Float}
 			case shaderir.Vec2F:
+				if err := checkArgsForVec2BuiltinFunc(args, argts); err != nil {
+					cs.addError(e.Pos(), err.Error())
+					return nil, nil, nil, false
+				}
 				t = shaderir.Type{Main: shaderir.Vec2}
 			case shaderir.Vec3F:
+				if err := checkArgsForVec3BuiltinFunc(args, argts); err != nil {
+					cs.addError(e.Pos(), err.Error())
+					return nil, nil, nil, false
+				}
 				t = shaderir.Type{Main: shaderir.Vec3}
 			case shaderir.Vec4F:
+				if err := checkArgsForVec4BuiltinFunc(args, argts); err != nil {
+					cs.addError(e.Pos(), err.Error())
+					return nil, nil, nil, false
+				}
 				t = shaderir.Type{Main: shaderir.Vec4}
 			case shaderir.Mat2F:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Mat2}
 			case shaderir.Mat3F:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Mat3}
 			case shaderir.Mat4F:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Mat4}
 			case shaderir.Step:
+				// TODO: Check arg types.
 				t = argts[1]
 			case shaderir.Smoothstep:
+				// TODO: Check arg types.
 				t = argts[2]
 			case shaderir.Length, shaderir.Distance, shaderir.Dot:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Float}
 			case shaderir.Cross:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Vec3}
 			case shaderir.Texture2DF:
+				// TODO: Check arg types.
 				t = shaderir.Type{Main: shaderir.Vec4}
 			default:
+				// TODO: Check arg types?
 				// If the argument is a non-typed constant value, treat is as a float value (#1874).
 				if args[0].Type == shaderir.NumberExpr && args[0].ConstType == shaderir.ConstTypeNone {
 					args[0].ConstType = shaderir.ConstTypeFloat
diff --git a/internal/shader/syntax_test.go b/internal/shader/syntax_test.go
index be4265ed0..bc396977b 100644
--- a/internal/shader/syntax_test.go
+++ b/internal/shader/syntax_test.go
@@ -1351,3 +1351,83 @@ func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
 		t.Errorf("error must be non-nil but was nil")
 	}
 }
+
+// Issue #2184
+func TestSyntaxBuiltinFuncType(t *testing.T) {
+	cases := []struct {
+		stmt string
+		err  bool
+	}{
+		{stmt: "a := vec2(1); _ = a", err: false},
+		{stmt: "a := vec2(1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec2(i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec2(i); _ = a", err: false},
+		{stmt: "a := vec2(vec2(1)); _ = a", err: false},
+		{stmt: "a := vec2(vec3(1)); _ = a", err: true},
+
+		{stmt: "a := vec2(1, 1); _ = a", err: false},
+		{stmt: "a := vec2(1.0, 1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec2(i, i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec2(i, i); _ = a", err: false},
+		{stmt: "a := vec2(vec2(1), 1); _ = a", err: true},
+		{stmt: "a := vec2(1, vec2(1)); _ = a", err: true},
+		{stmt: "a := vec2(vec2(1), vec2(1)); _ = a", err: true},
+		{stmt: "a := vec2(1, 1, 1); _ = a", err: true},
+
+		{stmt: "a := vec3(1); _ = a", err: false},
+		{stmt: "a := vec3(1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec3(i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec3(i); _ = a", err: false},
+		{stmt: "a := vec3(vec3(1)); _ = a", err: false},
+		{stmt: "a := vec3(vec2(1)); _ = a", err: true},
+		{stmt: "a := vec3(vec4(1)); _ = a", err: true},
+
+		{stmt: "a := vec3(1, 1, 1); _ = a", err: false},
+		{stmt: "a := vec3(1.0, 1.0, 1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec3(i, i, i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec3(i, i, i); _ = a", err: false},
+		{stmt: "a := vec3(vec2(1), 1); _ = a", err: false},
+		{stmt: "a := vec3(1, vec2(1)); _ = a", err: false},
+		{stmt: "a := vec3(vec3(1), 1); _ = a", err: true},
+		{stmt: "a := vec3(1, vec3(1)); _ = a", err: true},
+		{stmt: "a := vec3(vec3(1), vec3(1), vec3(1)); _ = a", err: true},
+		{stmt: "a := vec3(1, 1, 1, 1); _ = a", err: true},
+
+		{stmt: "a := vec4(1); _ = a", err: false},
+		{stmt: "a := vec4(1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec4(i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec4(i); _ = a", err: false},
+		{stmt: "a := vec4(vec4(1)); _ = a", err: false},
+		{stmt: "a := vec4(vec2(1)); _ = a", err: true},
+		{stmt: "a := vec4(vec3(1)); _ = a", err: true},
+
+		{stmt: "a := vec4(1, 1, 1, 1); _ = a", err: false},
+		{stmt: "a := vec4(1.0, 1.0, 1.0, 1.0); _ = a", err: false},
+		{stmt: "i := 1; a := vec4(i, i, i, i); _ = a", err: false},
+		{stmt: "i := 1.0; a := vec4(i, i, i, i); _ = a", err: false},
+		{stmt: "a := vec4(vec2(1), 1, 1); _ = a", err: false},
+		{stmt: "a := vec4(1, vec2(1), 1); _ = a", err: false},
+		{stmt: "a := vec4(1, 1, vec2(1)); _ = a", err: false},
+		{stmt: "a := vec4(vec2(1), vec2(1)); _ = a", err: false},
+		{stmt: "a := vec4(vec3(1), 1); _ = a", err: false},
+		{stmt: "a := vec4(1, vec3(1)); _ = a", err: false},
+		{stmt: "a := vec4(vec4(1), 1); _ = a", err: true},
+		{stmt: "a := vec4(1, vec4(1)); _ = a", err: true},
+		{stmt: "a := vec4(vec4(1), vec4(1), vec4(1), vec4(1)); _ = a", err: true},
+		{stmt: "a := vec4(1, 1, 1, 1, 1); _ = a", err: true},
+	}
+
+	for _, c := range cases {
+		_, err := compileToIR([]byte(fmt.Sprintf(`package main
+
+func Fragment(position vec4, texCoord vec2, color vec4) vec4 {
+	%s
+	return position
+}`, c.stmt)))
+		if err == nil && c.err {
+			t.Errorf("%s must return an error but does not", c.stmt)
+		} else if err != nil && !c.err {
+			t.Errorf("%s must not return nil but returned %v", c.stmt, err)
+		}
+	}
+}
diff --git a/internal/shader/type.go b/internal/shader/type.go
index 4e99d83d3..9b1ca0ee7 100644
--- a/internal/shader/type.go
+++ b/internal/shader/type.go
@@ -98,3 +98,124 @@ func (cs *compileState) parseType(block *block, expr ast.Expr) (shaderir.Type, b
 		return shaderir.Type{}, false
 	}
 }
+
+func canBeFloatImplicitly(expr shaderir.Expr, t shaderir.Type) bool {
+	// TODO: For integers, should only constants be allowed?
+	if t.Main == shaderir.Int {
+		return true
+	}
+	if t.Main == shaderir.Float {
+		return true
+	}
+	if expr.Const != nil {
+		if expr.Const.Kind() == gconstant.Int {
+			return true
+		}
+		if expr.Const.Kind() == gconstant.Float {
+			return true
+		}
+	}
+	return false
+}
+
+func checkArgsForVec2BuiltinFunc(args []shaderir.Expr, argts []shaderir.Type) error {
+	if len(args) != len(argts) {
+		return fmt.Errorf("the number of arguments and types doesn't match: %d vs %d", len(args), len(argts))
+	}
+
+	switch len(args) {
+	case 1:
+		if canBeFloatImplicitly(args[0], argts[0]) {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec2 {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec2: (%s)", argts[0].String())
+	case 2:
+		if canBeFloatImplicitly(args[0], argts[0]) && canBeFloatImplicitly(args[1], argts[1]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec2: (%s, %s)", argts[0].String(), argts[1].String())
+	default:
+		return fmt.Errorf("too many arguments for vec2")
+	}
+}
+
+func checkArgsForVec3BuiltinFunc(args []shaderir.Expr, argts []shaderir.Type) error {
+	if len(args) != len(argts) {
+		return fmt.Errorf("the number of arguments and types doesn't match: %d vs %d", len(args), len(argts))
+	}
+
+	switch len(args) {
+	case 1:
+		if canBeFloatImplicitly(args[0], argts[0]) {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec3 {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec3: (%s)", argts[0].String())
+	case 2:
+		if canBeFloatImplicitly(args[0], argts[0]) && argts[1].Main == shaderir.Vec2 {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec2 && canBeFloatImplicitly(args[1], argts[1]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec3: (%s, %s)", argts[0].String(), argts[1].String())
+	case 3:
+		if canBeFloatImplicitly(args[0], argts[0]) && canBeFloatImplicitly(args[1], argts[1]) && canBeFloatImplicitly(args[2], argts[2]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec3: (%s, %s, %s)", argts[0].String(), argts[1].String(), argts[2].String())
+	default:
+		return fmt.Errorf("too many arguments for vec3")
+	}
+}
+
+func checkArgsForVec4BuiltinFunc(args []shaderir.Expr, argts []shaderir.Type) error {
+	if len(args) != len(argts) {
+		return fmt.Errorf("the number of arguments and types doesn't match: %d vs %d", len(args), len(argts))
+	}
+
+	switch len(args) {
+	case 1:
+		if canBeFloatImplicitly(args[0], argts[0]) {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec4 {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec4: (%s)", argts[0].String())
+	case 2:
+		if canBeFloatImplicitly(args[0], argts[0]) && argts[1].Main == shaderir.Vec3 {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec2 && argts[1].Main == shaderir.Vec2 {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec3 && canBeFloatImplicitly(args[1], argts[1]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec4: (%s, %s)", argts[0].String(), argts[1].String())
+	case 3:
+		if canBeFloatImplicitly(args[0], argts[0]) && canBeFloatImplicitly(args[1], argts[1]) && argts[2].Main == shaderir.Vec2 {
+			return nil
+		}
+		if canBeFloatImplicitly(args[0], argts[0]) && argts[1].Main == shaderir.Vec2 && canBeFloatImplicitly(args[2], argts[2]) {
+			return nil
+		}
+		if argts[0].Main == shaderir.Vec2 && canBeFloatImplicitly(args[1], argts[1]) && canBeFloatImplicitly(args[2], argts[2]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec4: (%s, %s, %s)", argts[0].String(), argts[1].String(), argts[2].String())
+	case 4:
+		if canBeFloatImplicitly(args[0], argts[0]) && canBeFloatImplicitly(args[1], argts[1]) && canBeFloatImplicitly(args[2], argts[2]) && canBeFloatImplicitly(args[3], argts[3]) {
+			return nil
+		}
+		return fmt.Errorf("invalid arguments for vec4: (%s, %s, %s, %s)", argts[0].String(), argts[1].String(), argts[2].String(), argts[3].String())
+	default:
+		return fmt.Errorf("too many arguments for vec4")
+	}
+}