diff --git a/package-lock.json b/package-lock.json
index 3af2b2b4..9e3958a8 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
 	"name": "write-your-python-program",
-	"version": "1.1.0",
+	"version": "1.2.1",
 	"lockfileVersion": 3,
 	"requires": true,
 	"packages": {
 		"": {
 			"name": "write-your-python-program",
-			"version": "1.1.0",
+			"version": "1.2.1",
 			"license": "See license in LICENSE",
 			"dependencies": {
 				"@types/node": "^18.11.13",
diff --git a/python/fileTests b/python/fileTests
index 3279f251..c88d21de 100755
--- a/python/fileTests
+++ b/python/fileTests
@@ -288,6 +288,7 @@ checkWithOutputAux yes 1 test-data/testLiteral1.py
 checkWithOutputAux yes 0 test-data/testForwardTypeInRecord.py
 checkWithOutputAux yes 0 test-data/testForwardTypeInRecord2.py
 checkWithOutputAux yes 0 test-data/testUnionOfUnion.py
+checkWithOutputAux yes 1 test-data/testRecordTypes.py
 
 function is_min_version()
 {
diff --git a/python/src/runner.py b/python/src/runner.py
index 0b089255..8e2f514e 100644
--- a/python/src/runner.py
+++ b/python/src/runner.py
@@ -254,7 +254,7 @@ def __init__(self, mod, properlyImported):
                 if name and name[0] != '_':
                   d[name] = getattr(mod, name)
 
-def prepareLib(onlyCheckRunnable):
+def prepareLib(onlyCheckRunnable, enableTypeChecking):
     libDefs = None
     mod = INSTALLED_MODULE_NAME
     verbose('Attempting to import ' + mod)
@@ -262,6 +262,7 @@ def prepareLib(onlyCheckRunnable):
     libDefs = Lib(wypp, True)
     verbose('Successfully imported module ' + mod + ' from file ' + wypp.__file__)
     libDefs.initModule(enableChecks=not onlyCheckRunnable,
+                       enableTypeChecking=enableTypeChecking,
                        quiet=onlyCheckRunnable)
     return libDefs
 
@@ -534,7 +535,7 @@ def main(globals, argList=None):
     if not args.checkRunnable and (not args.quiet or args.verbose):
         printWelcomeString(fileToRun, version, useUntypy=args.checkTypes)
 
-    libDefs = prepareLib(onlyCheckRunnable=args.checkRunnable)
+    libDefs = prepareLib(onlyCheckRunnable=args.checkRunnable, enableTypeChecking=args.checkTypes)
 
     globals['__name__'] = '__wypp__'
     sys.modules['__wypp__'] = sys.modules['__main__']
diff --git a/python/src/writeYourProgram.py b/python/src/writeYourProgram.py
index b92d09eb..ce22370f 100644
--- a/python/src/writeYourProgram.py
+++ b/python/src/writeYourProgram.py
@@ -141,7 +141,10 @@ def _setattr(obj, k, v):
 def record(cls=None, mutable=False):
     def wrap(cls):
         newCls = dataclasses.dataclass(cls, frozen=not mutable)
-        return _patchDataClass(newCls, mutable)
+        if _typeCheckingEnabled:
+            return _patchDataClass(newCls, mutable)
+        else:
+            return newCls
     # See if we're being called as @record or @record().
     if cls is None:
         # We're called with parens.
@@ -155,6 +158,7 @@ def wrap(cls):
 _die = False
 
 def setDieOnCheckFailures(b):
+    global _die
     _die = b
 
 def _dieOnCheckFailures():
@@ -162,10 +166,12 @@ def _dieOnCheckFailures():
 
 _testCount = {'total': 0, 'failing': 0}
 _checksEnabled = True
+_typeCheckingEnabled = False
 
-def initModule(enableChecks=True, quiet=False):
-    global _checksEnabled
+def initModule(enableChecks=True, enableTypeChecking=True, quiet=False):
+    global _checksEnabled, _typeCheckingEnabled
     _checksEnabled = enableChecks
+    _typeCheckingEnabled = enableTypeChecking
     resetTestCount()
 
 def resetTestCount():
diff --git a/python/test-data/testRecordTypes.err b/python/test-data/testRecordTypes.err
new file mode 100644
index 00000000..84554590
--- /dev/null
+++ b/python/test-data/testRecordTypes.err
@@ -0,0 +1,12 @@
+Traceback (most recent call last):
+  File "test-data/testRecordTypes.py", line 8, in <module>
+    p = Point(1, '5')
+WyppTypeError: got value of wrong type
+given:    '5'
+expected: value of type int
+
+context: record constructor Point(x: int, y: int) -> Self
+                                             ^^^
+declared at: test-data/testRecordTypes.py:4
+caused by: test-data/testRecordTypes.py:8
+  | p = Point(1, '5')
diff --git a/python/test-data/testRecordTypes.err-3.12 b/python/test-data/testRecordTypes.err-3.12
new file mode 100644
index 00000000..37fbf43c
--- /dev/null
+++ b/python/test-data/testRecordTypes.err-3.12
@@ -0,0 +1,12 @@
+Traceback (most recent call last):
+  File "test-data/testRecordTypes.py", line 8, in <module>
+    p = Point(1, '5')
+WyppTypeError: got value of wrong type
+given:    '5'
+expected: value of type int
+
+context: record constructor Point(x: int, y: int) -> Self
+                                             ^^^
+declared at: test-data/testRecordTypes.py:3
+caused by: test-data/testRecordTypes.py:8
+  | p = Point(1, '5')
diff --git a/python/test-data/testRecordTypes.out b/python/test-data/testRecordTypes.out
new file mode 100644
index 00000000..e69de29b
diff --git a/python/test-data/testRecordTypes.py b/python/test-data/testRecordTypes.py
new file mode 100644
index 00000000..a9b58a5c
--- /dev/null
+++ b/python/test-data/testRecordTypes.py
@@ -0,0 +1,8 @@
+from wypp import *
+
+@record
+class Point:
+    x: int
+    y: int
+
+p = Point(1, '5')
diff --git a/python/tests/testRecord.py b/python/tests/testRecord.py
index 237b87e5..20a8b3db 100644
--- a/python/tests/testRecord.py
+++ b/python/tests/testRecord.py
@@ -4,6 +4,7 @@
 import traceback
 import dataclasses
 
+initModule()
 setDieOnCheckFailures(True)
 
 @record
diff --git a/src/programflow-visualization/constants.ts b/src/programflow-visualization/constants.ts
index 96d36c1d..476c0451 100644
--- a/src/programflow-visualization/constants.ts
+++ b/src/programflow-visualization/constants.ts
@@ -6,6 +6,13 @@ export namespace Variables {
 }
 
 export const nextLineExecuteHighlightType = vscode.window.createTextEditorDecorationType({
-  backgroundColor: 'rgba(255, 255, 0, 0.25)', // Yellow
+  borderWidth: '1px',
+  borderStyle: 'solid',
   isWholeLine: true,
+  borderColor: 'rgb(40, 40, 40)',
+  backgroundColor: 'rgba(248, 248, 181, 0.75)',
+  dark: {
+    borderColor: 'rgb(215, 215, 215)',
+    backgroundColor: 'rgba(75, 75, 24, 0.75)',
+  }
 });