diff --git a/common/changes/@cadl-lang/compiler/shared-symbol_2023-02-07-15-24.json b/common/changes/@cadl-lang/compiler/shared-symbol_2023-02-07-15-24.json
new file mode 100644
index 0000000000..dc7a84b724
--- /dev/null
+++ b/common/changes/@cadl-lang/compiler/shared-symbol_2023-02-07-15-24.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@cadl-lang/compiler",
+      "comment": "Fix issue with projectedName decorator not working correctly when multiple copies of the compiler are loaded.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@cadl-lang/compiler"
+}
\ No newline at end of file
diff --git a/common/changes/@cadl-lang/rest/shared-symbol_2023-02-07-17-20.json b/common/changes/@cadl-lang/rest/shared-symbol_2023-02-07-17-20.json
new file mode 100644
index 0000000000..d1b2df2db6
--- /dev/null
+++ b/common/changes/@cadl-lang/rest/shared-symbol_2023-02-07-17-20.json
@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@cadl-lang/rest",
+      "comment": "Fix issue with filtering of visibility decorator on resource key not working when multiple copies of the compiler are loaded.",
+      "type": "none"
+    }
+  ],
+  "packageName": "@cadl-lang/rest"
+}
\ No newline at end of file
diff --git a/packages/compiler/lib/decorators.ts b/packages/compiler/lib/decorators.ts
index 193081243e..deb08d4b2d 100644
--- a/packages/compiler/lib/decorators.ts
+++ b/packages/compiler/lib/decorators.ts
@@ -961,7 +961,7 @@ export function getOverloadedOperation(
   return program.stateMap(overloadsOperationKey).get(operation);
 }
 
-const projectedNameKey = Symbol("projectedNameKey");
+const projectedNameKey = createStateSymbol("projectedNameKey");
 
 /**
  * `@projectedName` - Indicate that this entity should be renamed according to the given projection.
diff --git a/packages/rest/src/http/operations.ts b/packages/rest/src/http/operations.ts
index 04076dfdf5..c6b72ae436 100644
--- a/packages/rest/src/http/operations.ts
+++ b/packages/rest/src/http/operations.ts
@@ -240,7 +240,9 @@ function validateProgram(program: Program, diagnostics: DiagnosticCollector) {
   // interpretation of visibility into the core.
   function checkForUnsupportedVisibility(property: ModelProperty) {
     if (getVisibility(program, property)?.includes("write")) {
-      const decorator = property.decorators.find((d) => d.decorator === $visibility);
+      // NOTE: Check for name equality instead of function equality
+      // to deal with multiple copies of core being used.
+      const decorator = property.decorators.find((d) => d.decorator.name === $visibility.name);
       const arg = decorator?.args.find(
         (a) => a.node?.kind === SyntaxKind.StringLiteral && a.node.value === "write"
       );
diff --git a/packages/rest/src/resource.ts b/packages/rest/src/resource.ts
index 4bc00597ab..2bde616fbd 100644
--- a/packages/rest/src/resource.ts
+++ b/packages/rest/src/resource.ts
@@ -97,10 +97,11 @@ function cloneKeyProperties(context: DecoratorContext, target: Model, resourceTy
     const { keyProperty } = resourceKey;
     const keyName = getKeyName(program, keyProperty);
 
-    // Filter out the @visibility decorator because it might affect metadata
-    // filtering
     const decorators = [
-      ...keyProperty.decorators.filter((d) => d.decorator !== $visibility),
+      // Filter out the @visibility decorator because it might affect metadata
+      // filtering. NOTE: Check for name equality instead of function equality
+      // to deal with multiple copies of core being used.
+      ...keyProperty.decorators.filter((d) => d.decorator.name !== $visibility.name),
       {
         decorator: $path,
         args: [],