diff --git a/vlib/compiler/gen_c.v b/vlib/compiler/gen_c.v
index 93ba15683a..c4a40ff392 100644
--- a/vlib/compiler/gen_c.v
+++ b/vlib/compiler/gen_c.v
@@ -516,6 +516,9 @@ fn (p mut Parser) cast(typ string) {
 		p.cgen.set_placeholder(pos, '*($typ*)(')
 	}
 	else {
+		if (is_number_type(expr_typ) || is_float_type(expr_typ))  && typ == 'bool' {
+			p.error('cannot cast a number to `bool`')
+		}	
 		p.cgen.set_placeholder(pos, '($typ)(')
 	}
 	p.check(.rpar)