diff --git a/docs/book/how-do-i-test-policies.md b/docs/book/how-do-i-test-policies.md
index 8808564626..4215bdd7e9 100644
--- a/docs/book/how-do-i-test-policies.md
+++ b/docs/book/how-do-i-test-policies.md
@@ -169,7 +169,7 @@ $ opa test --format=json pass_fail_error_test.rego
     },
     "package": "data.example",
     "name": "test_ok",
-    "duration": 610111
+    "duration": 618515
   },
   {
     "location": {
@@ -179,8 +179,8 @@ $ opa test --format=json pass_fail_error_test.rego
     },
     "package": "data.example",
     "name": "test_failure",
-    "fail": false,
-    "duration": 325989
+    "fail": true,
+    "duration": 322177
   },
   {
     "location": {
@@ -199,7 +199,7 @@ $ opa test --format=json pass_fail_error_test.rego
         "col": 5
       }
     },
-    "duration": 325903
+    "duration": 345148
   }
 ]
 ```
diff --git a/tester/reporter.go b/tester/reporter.go
index 0b7601b9ed..86136ebd2f 100644
--- a/tester/reporter.go
+++ b/tester/reporter.go
@@ -40,7 +40,7 @@ func (r PrettyReporter) Report(ch chan *Result) error {
 			pass++
 		} else if tr.Error != nil {
 			errs++
-		} else if tr.Fail != nil {
+		} else if tr.Fail {
 			fail++
 		}
 		if !tr.Pass() || r.Verbose {
diff --git a/tester/reporter_test.go b/tester/reporter_test.go
index 596803278a..ee2b12c129 100644
--- a/tester/reporter_test.go
+++ b/tester/reporter_test.go
@@ -8,12 +8,10 @@ import (
 
 func TestPrettyReporter(t *testing.T) {
 
-	var badResult interface{} = "fail"
-
 	ts := []*Result{
-		{nil, "data.foo.bar", "test_baz", nil, nil, 0},
-		{nil, "data.foo.bar", "test_qux", nil, fmt.Errorf("some err"), 0},
-		{nil, "data.foo.bar", "test_corge", &badResult, nil, 0},
+		{nil, "data.foo.bar", "test_baz", false, nil, 0},
+		{nil, "data.foo.bar", "test_qux", false, fmt.Errorf("some err"), 0},
+		{nil, "data.foo.bar", "test_corge", true, nil, 0},
 	}
 
 	var buf bytes.Buffer
diff --git a/tester/runner.go b/tester/runner.go
index 5cb37a337a..31a9d2bf0a 100644
--- a/tester/runner.go
+++ b/tester/runner.go
@@ -51,7 +51,7 @@ type Result struct {
 	Location *ast.Location `json:"location"`
 	Package  string        `json:"package"`
 	Name     string        `json:"name"`
-	Fail     *interface{}  `json:"fail,omitempty"`
+	Fail     bool          `json:"fail,omitempty"`
 	Error    error         `json:"error,omitempty"`
 	Duration time.Duration `json:"duration"`
 }
@@ -67,7 +67,7 @@ func newResult(loc *ast.Location, pkg, name string, duration time.Duration) *Res
 
 // Pass returns true if the test case passed.
 func (r Result) Pass() bool {
-	return r.Fail == nil && r.Error == nil
+	return !r.Fail && r.Error == nil
 }
 
 func (r *Result) String() string {
@@ -78,16 +78,12 @@ func (r *Result) outcome() string {
 	if r.Pass() {
 		return "PASS"
 	}
-	if r.Fail != nil {
+	if r.Fail {
 		return "FAIL"
 	}
 	return "ERROR"
 }
 
-func (r *Result) setFail(fail interface{}) {
-	r.Fail = &fail
-}
-
 // Runner implements simple test discovery and execution.
 type Runner struct {
 	compiler *ast.Compiler
@@ -184,9 +180,9 @@ func (r *Runner) runTest(ctx context.Context, mod *ast.Module, rule *ast.Rule) (
 			stop = true
 		}
 	} else if len(rs) == 0 {
-		tr.setFail(false)
+		tr.Fail = true
 	} else if b, ok := rs[0].Expressions[0].Value.(bool); !ok || !b {
-		tr.setFail(rs[0].Expressions[0].Value)
+		tr.Fail = true
 	}
 
 	return tr, stop
diff --git a/tester/runner_test.go b/tester/runner_test.go
index 88d93b140d..1321b603e8 100644
--- a/tester/runner_test.go
+++ b/tester/runner_test.go
@@ -56,7 +56,7 @@ func TestRun(t *testing.T) {
 			exp, ok := tests[k]
 			if !ok {
 				t.Errorf("Unexpected result for %v", k)
-			} else if exp.wantErr != (rs[i].Error != nil) || exp.wantFail != (rs[i].Fail != nil) {
+			} else if exp.wantErr != (rs[i].Error != nil) || exp.wantFail != rs[i].Fail {
 				t.Errorf("Expected %v for %v but got: %v", exp, k, rs[i])
 			}
 		}