diff --git a/src/core/friendly_errors/sketch_reader.js b/src/core/friendly_errors/sketch_reader.js
index c9c3159577..e229ad5bfc 100644
--- a/src/core/friendly_errors/sketch_reader.js
+++ b/src/core/friendly_errors/sketch_reader.js
@@ -319,12 +319,14 @@ if (typeof IS_MINIFIED !== 'undefined') {
       }
     }
     const keyArray = Object.keys(p5Constructors);
+    const globalFunctions = ['Renderer', 'Renderer2D', 'RendererGL'];
     let functionArray = [];
-    //get the names of all p5.js functions
-    for (let i = 0; i < keyArray.length; i++) {
-      functionArray.push(...Object.keys(p5Constructors[keyArray[i]].prototype));
+    //get the names of all p5.js functions which are available globally
+    for (let i = 0; i < globalFunctions.length; i++) {
+      functionArray.push(...Object.keys(
+        p5Constructors[globalFunctions[i]].prototype
+      ));
     }
-    functionArray = functionArray.filter(ele => !ele.includes('_'));
 
     //we have p5.js function names with us so we will check
     //if they have been declared or not.
diff --git a/test/unit/core/error_helpers.js b/test/unit/core/error_helpers.js
index e7a69eb6a2..e01ee1256d 100644
--- a/test/unit/core/error_helpers.js
+++ b/test/unit/core/error_helpers.js
@@ -961,7 +961,7 @@ suite('Tests for p5.js sketch_reader', function() {
   );
 
   testUnMinified(
-    'detects reassignment of p5.js function outside setup',
+    'detects reassignment of p5.js function (text) outside setup',
     function() {
       return new Promise(function(resolve) {
         prepSketchReaderTest(
@@ -975,6 +975,50 @@ suite('Tests for p5.js sketch_reader', function() {
     }
   );
 
+  testUnMinified(
+    'detects reassignment of p5.js function (textSize from Typography) outside setup',
+    function() {
+      return new Promise(function(resolve) {
+        prepSketchReaderTest(
+          ['let textSize = 100', 'function setup() {}'],
+          resolve
+        );
+      }).then(function() {
+        assert.strictEqual(log.length, 1);
+        assert.match(log[0], /you have used a p5.js reserved function/);
+      });
+    }
+  );
+
+  testUnMinified(
+    'does not detect reassignment of p5.js function (size from TypedDict or Dom) outside setup',
+    function() {
+      return new Promise(function(resolve) {
+        prepSketchReaderTest(
+          ['let size = 100', 'function setup() {}'],
+          resolve
+        );
+      }).then(function() {
+        assert.strictEqual(log.length, 0);
+      });
+    }
+  );
+
+  testUnMinified(
+    'detects reassignment of p5.js function (point from shape) outside setup',
+    function() {
+      return new Promise(function(resolve) {
+        prepSketchReaderTest(
+          ['let point = 100', 'function setup() {}'],
+          resolve
+        );
+      }).then(function() {
+        assert.strictEqual(log.length, 1);
+        assert.match(log[0], /you have used a p5.js reserved function/);
+      });
+    }
+  );
+
   testUnMinified(
     'detects reassignment of p5.js functions in declaration lists',
     function() {