diff --git a/src/main/java/org/json/JSONObject.java b/src/main/java/org/json/JSONObject.java
index b504519..10fed95 100644
--- a/src/main/java/org/json/JSONObject.java
+++ b/src/main/java/org/json/JSONObject.java
@@ -213,6 +213,7 @@ public class JSONObject {
         this();
         char c;
         String key;
+        Object obj;
 
         boolean isInitial = x.getPrevious() == 0;
 
@@ -230,7 +231,20 @@ public class JSONObject {
                 }
                 return;
             default:
-                key = x.nextSimpleValue(c).toString();
+                obj = x.nextSimpleValue(c);
+                key = obj.toString();
+            }
+
+            if (jsonParserConfiguration != null && jsonParserConfiguration.isStrictMode()) {
+                if(obj instanceof Boolean) {
+                    throw x.syntaxError(String.format("Strict mode error: key '%s' cannot be boolean", key));
+                }
+                if(obj == JSONObject.NULL) {
+                    throw x.syntaxError(String.format("Strict mode error: key '%s' cannot be null", key));
+                }
+                if(obj instanceof Number) {
+                    throw x.syntaxError(String.format("Strict mode error: key '%s' cannot be number", key));
+                }
             }
 
             // The key is followed by ':'.
diff --git a/src/main/java/org/json/JSONTokener.java b/src/main/java/org/json/JSONTokener.java
index a90d51a..ffe12d6 100644
--- a/src/main/java/org/json/JSONTokener.java
+++ b/src/main/java/org/json/JSONTokener.java
@@ -511,6 +511,15 @@ public class JSONTokener {
             throw this.syntaxError("Missing value");
         }
         Object obj = JSONObject.stringToValue(string);
+        // if obj is a boolean, look at string
+        if (jsonParserConfiguration != null &&
+                jsonParserConfiguration.isStrictMode() && obj instanceof Boolean) {
+            if (!"true".equals(string) && !"false".equals(string)) {
+                throw this.syntaxError(String.format("Strict mode error: Value '%s' is not lowercase boolean", obj));
+            }
+        }
+
+
         // Strict mode only allows strings with explicit double quotes
         if (jsonParserConfiguration != null &&
                 jsonParserConfiguration.isStrictMode() &&
diff --git a/src/test/java/org/json/junit/JSONObjectTest.java b/src/test/java/org/json/junit/JSONObjectTest.java
index 061f185..50319a8 100644
--- a/src/test/java/org/json/junit/JSONObjectTest.java
+++ b/src/test/java/org/json/junit/JSONObjectTest.java
@@ -3997,6 +3997,41 @@ public class JSONObjectTest {
         assertThrows(JSONException.class, () -> { new JSONObject(tokener); });
     }
 
+    @Test
+    public void test_strictModeWithMisCasedBooleanValue(){
+        JSONParserConfiguration jsonParserConfiguration = new JSONParserConfiguration().withStrictMode();
+
+        try{
+            JSONObject j1 = new JSONObject("{\"a\":True}", jsonParserConfiguration);
+            fail("Expected an exception");
+        } catch (JSONException e) { }
+        try{
+            JSONObject j2 = new JSONObject("{\"a\":TRUE}", jsonParserConfiguration);
+            fail("Expected an exception");
+        } catch (JSONException e) { }
+    }
+
+    @Test
+    public void test_strictModeWithInappropriateKey(){
+        JSONParserConfiguration jsonParserConfiguration = new JSONParserConfiguration().withStrictMode();
+
+        // Parsing the following objects should fail
+        try{
+            JSONObject j3 = new JSONObject("{true : 3}", jsonParserConfiguration);
+            fail("Expected an exception");
+        } catch (JSONException e) { }
+        try{
+            JSONObject j4 = new JSONObject("{TRUE : 3}", jsonParserConfiguration);
+            fail("Expected an exception");
+        } catch (JSONException e) { }
+        try{
+            JSONObject j5 = new JSONObject("{1 : 3}", jsonParserConfiguration);
+            fail("Expected an exception");
+        } catch (JSONException e) { }
+
+    }
+
+
     /**
      * Method to build nested map of max maxDepth
      *