diff --git a/internal/shaderir/glsl.go b/internal/shaderir/glsl.go
index 4314b2404..e6d08fc34 100644
--- a/internal/shaderir/glsl.go
+++ b/internal/shaderir/glsl.go
@@ -254,7 +254,8 @@ func (p *Program) glslBlock(b *Block, level int, localVarIndex int) []string {
 			for _, exp := range e.Exprs[1:] {
 				args = append(args, glslExpr(&exp))
 			}
-			return fmt.Sprintf("(%s)(%s)", glslExpr(&e.Exprs[0]), strings.Join(args, ", "))
+			// Using parentheses at the callee is illegal.
+			return fmt.Sprintf("%s(%s)", glslExpr(&e.Exprs[0]), strings.Join(args, ", "))
 		case FieldSelector:
 			return fmt.Sprintf("(%s).%s", glslExpr(&e.Exprs[0]), glslExpr(&e.Exprs[1]))
 		case Index:
diff --git a/internal/shaderir/ir_test.go b/internal/shaderir/ir_test.go
index 25ee40334..99f6efeed 100644
--- a/internal/shaderir/ir_test.go
+++ b/internal/shaderir/ir_test.go
@@ -456,12 +456,12 @@ varying vec3 V0;`,
 				},
 			},
 			GlslVS: `void F0(in float l0, in float l1, out vec2 l2) {
-	(F1)();
-	l2 = (F2)(l0, l1);
+	F1();
+	l2 = F2(l0, l1);
 }`,
 			GlslFS: `void F0(in float l0, in float l1, out vec2 l2) {
-	(F1)();
-	l2 = (F2)(l0, l1);
+	F1();
+	l2 = F2(l0, l1);
 }`,
 		},
 		{
@@ -492,10 +492,10 @@ varying vec3 V0;`,
 				},
 			},
 			GlslVS: `void F0(in float l0, in float l1, out float l2) {
-	l2 = (min)(l0, l1);
+	l2 = min(l0, l1);
 }`,
 			GlslFS: `void F0(in float l0, in float l1, out float l2) {
-	l2 = (min)(l0, l1);
+	l2 = min(l0, l1);
 }`,
 		},
 		{