diff --git a/pkg/apis/pipeline/v1beta1/pipeline_validation_test.go b/pkg/apis/pipeline/v1beta1/pipeline_validation_test.go
index 8faf62c9182..234f7832676 100644
--- a/pkg/apis/pipeline/v1beta1/pipeline_validation_test.go
+++ b/pkg/apis/pipeline/v1beta1/pipeline_validation_test.go
@@ -272,7 +272,7 @@ func TestPipeline_Validate_Failure(t *testing.T) {
 			},
 		},
 		expectedError: apis.FieldError{
-			Message: `non-existent variable in "$(params.doesnotexist)"`,
+			Message: "non-existent variable `doesnotexist` in \"$(params.doesnotexist)\"",
 			Paths:   []string{"spec.tasks[0].steps[0].script"},
 		},
 	}, {
@@ -303,7 +303,7 @@ func TestPipeline_Validate_Failure(t *testing.T) {
 			},
 		},
 		expectedError: apis.FieldError{
-			Message: `non-existent variable in "$(params.doesnotexist)"`,
+			Message: "non-existent variable `doesnotexist` in \"$(params.doesnotexist)\"",
 			Paths:   []string{"spec.finally[0].steps[0].script"},
 		},
 	}, {
diff --git a/pkg/apis/pipeline/v1beta1/task_validation.go b/pkg/apis/pipeline/v1beta1/task_validation.go
index 4d03a950125..a4c0725338a 100644
--- a/pkg/apis/pipeline/v1beta1/task_validation.go
+++ b/pkg/apis/pipeline/v1beta1/task_validation.go
@@ -640,7 +640,7 @@ func validateTaskResultsVariables(ctx context.Context, steps []Step, results []T
 		resultsNames.Insert(r.Name)
 	}
 	for idx, step := range steps {
-		errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariables(step.Script, "results", resultsNames).ViaField("script").ViaFieldIndex("steps", idx))
+		errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariablesWithDetail(step.Script, "results", resultsNames).ViaField("script").ViaFieldIndex("steps", idx))
 	}
 	return errs
 }
@@ -790,7 +790,7 @@ func validateStepVariables(ctx context.Context, step Step, prefix string, vars s
 	errs := substitution.ValidateNoReferencesToUnknownVariables(step.Name, prefix, vars).ViaField("name")
 	errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariables(step.Image, prefix, vars).ViaField("image"))
 	errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariables(step.WorkingDir, prefix, vars).ViaField("workingDir"))
-	errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariables(step.Script, prefix, vars).ViaField("script"))
+	errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariablesWithDetail(step.Script, prefix, vars).ViaField("script"))
 	for i, cmd := range step.Command {
 		errs = errs.Also(substitution.ValidateNoReferencesToUnknownVariables(cmd, prefix, vars).ViaFieldIndex("command", i))
 	}
diff --git a/pkg/apis/pipeline/v1beta1/task_validation_test.go b/pkg/apis/pipeline/v1beta1/task_validation_test.go
index fec9351b99e..69bbd1ade2c 100644
--- a/pkg/apis/pipeline/v1beta1/task_validation_test.go
+++ b/pkg/apis/pipeline/v1beta1/task_validation_test.go
@@ -858,7 +858,7 @@ func TestTaskSpecValidateError(t *testing.T) {
 			Results: []v1beta1.TaskResult{{Name: "a-result"}},
 		},
 		expectedError: apis.FieldError{
-			Message: `non-existent variable in "\n\t\t\t\t#!/usr/bin/env bash\n\t\t\t\tdate | tee $(results.non-exist.path)"`,
+			Message: `non-existent variable ` + "`non-exist`" + ` in "\n\t\t\t\t#!/usr/bin/env bash\n\t\t\t\tdate | tee $(results.non-exist.path)"`,
 			Paths:   []string{"steps[0].script"},
 		},
 	}, {
@@ -1417,7 +1417,7 @@ func TestTaskSpecValidateError(t *testing.T) {
 			}},
 		},
 		expectedError: apis.FieldError{
-			Message: `non-existent variable in "\n\t\t\t\t#!/usr/bin/env  bash\n\t\t\t\thello \"$(context.task.missing)\""`,
+			Message: `non-existent variable ` + "`missing`" + ` in "\n\t\t\t\t#!/usr/bin/env  bash\n\t\t\t\thello \"$(context.task.missing)\""`,
 			Paths:   []string{"steps[0].script"},
 		},
 	}, {
@@ -2566,7 +2566,7 @@ func TestTaskSpecValidate_StepResults_Error(t *testing.T) {
 			Results: []v1.StepResult{{Name: "a-result"}},
 		},
 		expectedError: apis.FieldError{
-			Message: `non-existent variable in "\n\t\t\t#!/usr/bin/env bash\n\t\t\tdate | tee $(results.non-exist.path)"`,
+			Message: "non-existent variable `non-exist` in \"\\n\\t\\t\\t#!/usr/bin/env bash\\n\\t\\t\\tdate | tee $(results.non-exist.path)\": steps[0].script\nnon-existent variable in \"\\n\\t\\t\\t#!/usr/bin/env bash\\n\\t\\t\\tdate | tee $(results.non-exist.path)\"",
 			Paths:   []string{"steps[0].script"},
 		},
 		enableStepActions: true,
diff --git a/pkg/substitution/substitution.go b/pkg/substitution/substitution.go
index 8e1acab2fe1..df428c31bf5 100644
--- a/pkg/substitution/substitution.go
+++ b/pkg/substitution/substitution.go
@@ -54,6 +54,16 @@ var intIndexRegex = regexp.MustCompile(intIndex)
 // - prefix: the prefix of the substitutable variable, e.g. "params" or "context.pipeline"
 // - vars: names of known variables
 func ValidateNoReferencesToUnknownVariables(value, prefix string, vars sets.String) *apis.FieldError {
+	return validateNoReferencesToUnknownVariables(value, prefix, vars, false)
+}
+
+// ValidateNoReferencesToUnknownVariablesWithDetail same as ValidateNoReferencesToUnknownVariables
+// but with more prefix detailed error message
+func ValidateNoReferencesToUnknownVariablesWithDetail(value, prefix string, vars sets.String) *apis.FieldError {
+	return validateNoReferencesToUnknownVariables(value, prefix, vars, true)
+}
+
+func validateNoReferencesToUnknownVariables(value, prefix string, vars sets.String, withDetail bool) *apis.FieldError {
 	if vs, present, errString := ExtractVariablesFromString(value, prefix); present {
 		if errString != "" {
 			return &apis.FieldError{
@@ -64,8 +74,14 @@ func ValidateNoReferencesToUnknownVariables(value, prefix string, vars sets.Stri
 		for _, v := range vs {
 			v = TrimArrayIndex(v)
 			if !vars.Has(v) {
+				var msg string
+				if withDetail {
+					msg = fmt.Sprintf("non-existent variable `%s` in %q", v, value)
+				} else {
+					msg = fmt.Sprintf("non-existent variable in %q", value)
+				}
 				return &apis.FieldError{
-					Message: fmt.Sprintf("non-existent variable in %q", value),
+					Message: msg,
 					// Empty path is required to make the `ViaField`, … work
 					Paths: []string{""},
 				}
diff --git a/pkg/substitution/substitution_test.go b/pkg/substitution/substitution_test.go
index c265510d195..0599008dfba 100644
--- a/pkg/substitution/substitution_test.go
+++ b/pkg/substitution/substitution_test.go
@@ -189,6 +189,49 @@ func TestValidateNoReferencesToUnknownVariables(t *testing.T) {
 	}
 }
 
+func TestValidateNoReferencesToUnknownVariablesWithDetail(t *testing.T) {
+	type args struct {
+		input  string
+		prefix string
+		vars   sets.String
+	}
+	for _, tc := range []struct {
+		name          string
+		args          args
+		expectedError *apis.FieldError
+	}{{
+		name: "undefined variable",
+		args: args{
+			input:  "--flag=$(inputs.params.baz)",
+			prefix: "inputs.params",
+			vars:   sets.NewString("foo"),
+		},
+		expectedError: &apis.FieldError{
+			Message: `non-existent variable ` + "`baz`" + ` in "--flag=$(inputs.params.baz)"`,
+			Paths:   []string{""},
+		},
+	}, {
+		name: "undefined individual attributes of an object param",
+		args: args{
+			input:  "--flag=$(params.objectParam.key3)",
+			prefix: "params.objectParam",
+			vars:   sets.NewString("key1", "key2"),
+		},
+		expectedError: &apis.FieldError{
+			Message: `non-existent variable ` + "`key3`" + ` in "--flag=$(params.objectParam.key3)"`,
+			Paths:   []string{""},
+		},
+	}} {
+		t.Run(tc.name, func(t *testing.T) {
+			got := substitution.ValidateNoReferencesToUnknownVariablesWithDetail(tc.args.input, tc.args.prefix, tc.args.vars)
+
+			if d := cmp.Diff(tc.expectedError, got, cmp.AllowUnexported(apis.FieldError{})); d != "" {
+				t.Errorf("ValidateVariableP() error did not match expected error %s", diff.PrintWantGot(d))
+			}
+		})
+	}
+}
+
 func TestValidateNoReferencesToProhibitedVariables(t *testing.T) {
 	type args struct {
 		input  string