diff --git a/micrometer-observation-test/src/main/java/io/micrometer/observation/tck/ObservationValidator.java b/micrometer-observation-test/src/main/java/io/micrometer/observation/tck/ObservationValidator.java
index 1c701bfee0..5d94e33a99 100644
--- a/micrometer-observation-test/src/main/java/io/micrometer/observation/tck/ObservationValidator.java
+++ b/micrometer-observation-test/src/main/java/io/micrometer/observation/tck/ObservationValidator.java
@@ -117,10 +117,7 @@ public boolean supportsContext(Context context) {
     }
 
     private void addHistoryElement(Context context, EventName eventName) {
-        if (!context.containsKey(History.class)) {
-            context.put(History.class, new History());
-        }
-        History history = context.get(History.class);
+        History history = context.computeIfAbsent(History.class, clazz -> new History());
         history.addHistoryElement(eventName);
     }
 
@@ -147,7 +144,7 @@ private Status checkIfObservationWasStartedButNotStopped(String prefix, Context
     }
 
     private static void throwInvalidObservationException(ValidationResult validationResult) {
-        History history = validationResult.getContext().getOrDefault(History.class, new History());
+        History history = validationResult.getContext().getOrDefault(History.class, () -> new History());
         throw new InvalidObservationException(validationResult.getMessage(), validationResult.getContext(),
                 history.getHistoryElements());
     }
diff --git a/micrometer-observation-test/src/test/java/io/micrometer/observation/tck/ObservationValidatorTests.java b/micrometer-observation-test/src/test/java/io/micrometer/observation/tck/ObservationValidatorTests.java
index eeb5c5b06e..ca3c595824 100644
--- a/micrometer-observation-test/src/test/java/io/micrometer/observation/tck/ObservationValidatorTests.java
+++ b/micrometer-observation-test/src/test/java/io/micrometer/observation/tck/ObservationValidatorTests.java
@@ -43,7 +43,7 @@ void doubleStartShouldBeInvalid() {
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid start: Observation 'test' has already been started\n"
                             + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
-                            + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -54,7 +54,7 @@ void stopBeforeStartShouldBeInvalid() {
             .hasMessage("Invalid stop: Observation 'test' has not been started yet")
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid stop: Observation 'test' has not been started yet\n"
-                            + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$stopBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$stopBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -65,7 +65,7 @@ void errorBeforeStartShouldBeInvalid() {
             .hasMessage("Invalid error signal: Observation 'test' has not been started yet")
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid error signal: Observation 'test' has not been started yet\n"
-                            + "ERROR: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "ERROR: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -76,7 +76,7 @@ void eventBeforeStartShouldBeInvalid() {
             .hasMessage("Invalid event signal: Observation 'test' has not been started yet")
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid event signal: Observation 'test' has not been started yet\n"
-                            + "EVENT: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "EVENT: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -89,7 +89,7 @@ void scopeBeforeStartShouldBeInvalid() {
             .hasMessage("Invalid scope opening: Observation 'test' has not been started yet")
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid scope opening: Observation 'test' has not been started yet\n"
-                            + "SCOPE_OPEN: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$scopeBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "SCOPE_OPEN: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$scopeBeforeStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -101,7 +101,7 @@ void observeAfterStartShouldBeInvalid() {
             .satisfies(exception -> assertThat(exception.toString()).matches(
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid start: Observation 'test' has already been started\n"
                             + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$observeAfterStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
-                            + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$observeAfterStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$observeAfterStartShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -117,7 +117,7 @@ void doubleStopShouldBeInvalid() {
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid stop: Observation 'test' has already been stopped\n"
                             + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
                             + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
-                            + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$doubleStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -133,7 +133,7 @@ void errorAfterStopShouldBeInvalid() {
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid error signal: Observation 'test' has already been stopped\n"
                             + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
                             + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
-                            + "ERROR: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "ERROR: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$errorAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test
@@ -149,7 +149,7 @@ void eventAfterStopShouldBeInvalid() {
                     "(?s)^io\\.micrometer\\.observation\\.tck\\.InvalidObservationException: Invalid event signal: Observation 'test' has already been stopped\n"
                             + "START: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
                             + "STOP: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)\n"
-                            + "EVENT: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests.java:\\d+\\)$"));
+                            + "EVENT: app//io\\.micrometer\\.observation\\.tck\\.ObservationValidatorTests\\.lambda\\$eventAfterStopShouldBeInvalid\\$\\d+\\(ObservationValidatorTests\\.java:\\d+\\)$"));
     }
 
     @Test