diff --git a/tests/expr.test b/tests/expr.test
index 190e963aa03..7563757834c 100644
--- a/tests/expr.test
+++ b/tests/expr.test
@@ -506,10 +506,10 @@ test expr-11.14 {CompileAddExpr: runtime error} {
 } {1 {cannot use a list as right operand of "+"}}
 test expr-11.15 {CompileAddExpr: runtime error} {
     list [catch {expr {{1 2 3}+24.0}} msg] $msg
-} {1 {cannot use a list as left operand of "+"}}
+} {1 {cannot use non-numeric string "1 2 3" as left operand of "+"}}
 test expr-11.16 {CompileAddExpr: runtime error} {
     list [catch {expr {~[dict create foo bar]}} msg] $msg
-} {1 {cannot use a list as operand of "~"}}
+} {1 {cannot use non-numeric string "foo bar" as operand of "~"}}
 
 test expr-12.1 {CompileMultiplyExpr: just unary expr} {expr ~4} -5
 test expr-12.2 {CompileMultiplyExpr: just unary expr} {expr --5} 5