diff --git a/src/cmd/internal/test2json/test2json.go b/src/cmd/internal/test2json/test2json.go
index 3e09c8d915..a113c2e0ee 100644
--- a/src/cmd/internal/test2json/test2json.go
+++ b/src/cmd/internal/test2json/test2json.go
@@ -226,6 +226,7 @@ func (c *converter) handleInputLine(line []byte) {
 		if len(c.report) < indent {
 			// Nested deeper than expected.
 			// Treat this line as plain output.
+			c.output.write(origLine)
 			return
 		}
 		// Flush reports at this indentation level or deeper.
diff --git a/src/cmd/internal/test2json/testdata/issue23036.json b/src/cmd/internal/test2json/testdata/issue23036.json
new file mode 100644
index 0000000000..935c0c5fc0
--- /dev/null
+++ b/src/cmd/internal/test2json/testdata/issue23036.json
@@ -0,0 +1,12 @@
+{"Action":"run","Test":"TestActualCase"}
+{"Action":"output","Test":"TestActualCase","Output":"=== RUN   TestActualCase\n"}
+{"Action":"output","Test":"TestActualCase","Output":"--- FAIL: TestActualCase (0.00s)\n"}
+{"Action":"output","Test":"TestActualCase","Output":"        foo_test.go:14: Differed.\n"}
+{"Action":"output","Test":"TestActualCase","Output":"                Expected: MyTest:\n"}
+{"Action":"output","Test":"TestActualCase","Output":"                --- FAIL: Test output from other tool\n"}
+{"Action":"output","Test":"TestActualCase","Output":"                Actual: not expected\n"}
+{"Action":"fail","Test":"TestActualCase"}
+{"Action":"output","Output":"FAIL\n"}
+{"Action":"output","Output":"exit status 1\n"}
+{"Action":"output","Output":"FAIL    github.com/org/project/badtest     0.049s\n"}
+{"Action":"fail"}
diff --git a/src/cmd/internal/test2json/testdata/issue23036.test b/src/cmd/internal/test2json/testdata/issue23036.test
new file mode 100644
index 0000000000..fd4774f4b6
--- /dev/null
+++ b/src/cmd/internal/test2json/testdata/issue23036.test
@@ -0,0 +1,9 @@
+=== RUN   TestActualCase
+--- FAIL: TestActualCase (0.00s)
+        foo_test.go:14: Differed.
+                Expected: MyTest:
+                --- FAIL: Test output from other tool
+                Actual: not expected
+FAIL
+exit status 1
+FAIL    github.com/org/project/badtest     0.049s