diff --git a/data-prepper-expression/build.gradle b/data-prepper-expression/build.gradle
index 9e5123292f..e4757942d7 100644
--- a/data-prepper-expression/build.gradle
+++ b/data-prepper-expression/build.gradle
@@ -42,7 +42,7 @@ jacocoTestCoverageVerification {
     violationRules {
         rule { //in addition to core projects rule - this one checks for 100% code coverage for this project
             limit {
-                minimum = 0.9 // lowered because ParseTreeCoercionServiceTest does not mock enough, and it is not possible to induce a failure
+                minimum = 1.0 // lowered because ParseTreeCoercionServiceTest does not mock enough, and it is not possible to induce a failure
             }
         }
     }
diff --git a/data-prepper-expression/src/test/java/org/opensearch/dataprepper/expression/ParseTreeCoercionServiceTest.java b/data-prepper-expression/src/test/java/org/opensearch/dataprepper/expression/ParseTreeCoercionServiceTest.java
index 3fc9fcd4e5..4dca1dc812 100644
--- a/data-prepper-expression/src/test/java/org/opensearch/dataprepper/expression/ParseTreeCoercionServiceTest.java
+++ b/data-prepper-expression/src/test/java/org/opensearch/dataprepper/expression/ParseTreeCoercionServiceTest.java
@@ -25,6 +25,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Function;
 import java.util.stream.Stream;
 
@@ -186,6 +187,32 @@ void testCoerceTerminalNodeEscapeJsonPointerTypeSupportedValues(final Object tes
         }
     }
 
+    @Test
+    void testCoerceTerminalNodeEscapeJsonPointerTypeUnSupportedValues() {
+        final String testKey = "testKey";
+        final AtomicBoolean testValue = new AtomicBoolean();
+        final String testEscapeJsonPointerKey = String.format("\"/%s\"", testKey);
+        final Event testEvent = createInvalidTestEvent(Map.of(testKey, testValue));
+        when(token.getType()).thenReturn(DataPrepperExpressionParser.EscapedJsonPointer);
+        when(terminalNode.getSymbol()).thenReturn(token);
+        when(terminalNode.getText()).thenReturn(testEscapeJsonPointerKey);
+        assertThrows(ExpressionCoercionException.class, () -> objectUnderTest.coercePrimaryTerminalNode(terminalNode, testEvent));
+    }
+
+    @Test
+    void testCoerceTerminalNodeJsonPointerTypeUnSupportedValues() {
+        final String testKey1 = "key1";
+        final String testKey2 = "key2";
+        final AtomicBoolean testValue = new AtomicBoolean();
+        final String testJsonPointerKey = String.format("/%s/%s", testKey1, testKey2);
+
+        final Event testEvent = createInvalidTestEvent(Map.of(testKey1, testValue));
+        when(token.getType()).thenReturn(DataPrepperExpressionParser.JsonPointer);
+        when(terminalNode.getSymbol()).thenReturn(token);
+        when(terminalNode.getText()).thenReturn(testJsonPointerKey);
+        assertThrows(ExpressionCoercionException.class, () -> objectUnderTest.coercePrimaryTerminalNode(terminalNode, testEvent));
+    }
+
     @Test
     void testCoerceTerminalNodeUnsupportedType() {
         final Event testEvent = createTestEvent(new HashMap<>());
@@ -306,6 +333,12 @@ private Event createTestEvent(final Object data) {
         return event;
     }
 
+    private Event createInvalidTestEvent(final Object data) {
+        final Event event = mock(Event.class);
+        lenient().when(event.get(anyString(), any())).thenReturn(new AtomicBoolean());
+        return event;
+    }
+
     private static Stream<Arguments> provideKeys() {
         return Stream.of(
                 Arguments.of("test key", "\"/test key\""),