diff --git a/src/compiler.ts b/src/compiler.ts
index d9dd2df4cc..03b61615fa 100644
--- a/src/compiler.ts
+++ b/src/compiler.ts
@@ -6053,8 +6053,13 @@ export class Compiler extends DiagnosticEmitter {
           ], valueExpression);
         }
       }
+      default: {
+        this.error(
+          DiagnosticCode.The_target_of_an_assignment_must_be_a_variable_or_a_property_access,
+          valueExpression.range
+        );
+      }
     }
-    assert(false);
     return module.unreachable();
   }
 
@@ -9241,9 +9246,6 @@ export class Compiler extends DiagnosticEmitter {
       Constraints.NONE
     );
 
-    // shortcut if compiling the getter already failed
-    if (getExpressionId(getValue) == ExpressionId.Unreachable) return getValue;
-
     // if the value isn't dropped, a temp. local is required to remember the original value,
     // except if a static overload is found, which reverses the use of a temp. (see below)
     var tempLocal: Local | null = null;
diff --git a/tests/compiler/unary-errors.json b/tests/compiler/unary-errors.json
new file mode 100644
index 0000000000..a855e5c66a
--- /dev/null
+++ b/tests/compiler/unary-errors.json
@@ -0,0 +1,40 @@
+{
+  "asc_flags": [
+  ],
+  "stderr": [
+    "AS234: Expression does not compile to a value at runtime.",
+    "const a = (Foo++);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const a = (Foo++);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const b = (++Foo);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const b = (++Foo);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const d = (Foo--);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const d = (Foo--);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const e = (--Foo);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const e = (--Foo);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const g = (Bar++);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const g = (Bar++);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const h = (++Bar);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const h = (++Bar);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const j = (Bar--);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const j = (Bar--);",
+    "AS234: Expression does not compile to a value at runtime.",
+    "const k = (--Bar);",
+    "TS2541: The target of an assignment must be a variable or a property access.",
+    "const k = (--Bar);",
+    "AS102: User-defined: \"EOF\"",
+    "ERROR(\"EOF\");"
+  ]
+}
diff --git a/tests/compiler/unary-errors.ts b/tests/compiler/unary-errors.ts
new file mode 100644
index 0000000000..4e42d032a7
--- /dev/null
+++ b/tests/compiler/unary-errors.ts
@@ -0,0 +1,23 @@
+/* eslint-disable no-class-assign */
+/* eslint-disable no-global-assign */
+
+class Foo {}
+namespace Bar {}
+
+const a = (Foo++);
+const b = (++Foo);
+// const c = (Foo += 1);
+
+const d = (Foo--);
+const e = (--Foo);
+// const f = (Foo -= 1);
+
+const g = (Bar++);
+const h = (++Bar);
+// const i = (Bar += 1);
+
+const j = (Bar--);
+const k = (--Bar);
+// const l = (Bar -= 1);
+
+ERROR("EOF");  
\ No newline at end of file