diff --git a/src/lens.ts b/src/lens.ts
index a60037a..40f2e7a 100644
--- a/src/lens.ts
+++ b/src/lens.ts
@@ -9,6 +9,7 @@ import { cleanFilename } from './utils';
 import logger from './log';
 import { InfracostCommand } from './command';
 import context from './context';
+import path = require('path');
 
 export default class InfracostLensProvider implements CodeLensProvider {
   workspace: Workspace;
@@ -26,12 +27,11 @@ export default class InfracostLensProvider implements CodeLensProvider {
     }
 
     const lenses: CodeLens[] = [];
-    const filename = cleanFilename(document.uri.path);
+    const filename = document.uri.fsPath;
     logger.debug(`providing codelens for file ${filename}`);
-
     const blocks = this.workspace.project(filename);
     for (const block of Object.values(blocks)) {
-      if (block.filename !== filename) {
+      if (block.filename.toLowerCase() !== filename.toLowerCase()) {
         continue;
       }
 
diff --git a/src/workspace.ts b/src/workspace.ts
index be0f1f3..b52e9da 100644
--- a/src/workspace.ts
+++ b/src/workspace.ts
@@ -155,10 +155,12 @@ export default class Workspace {
 
   // TODO: determine or allow users to switch the project they are using.
   project(filename: string): { [key: string]: Block } {
-    const projects = this.filesToProjects[filename];
-
-    if (projects && Object.keys(projects).length > 0) {
-      const project = Object.keys(projects)[0];
+    const key = filename.split(path.sep).join('/');
+     const projectKey = this.filesToProjects[Object.keys(this.filesToProjects).find((k: string) => k.toLowerCase() === key.toLowerCase()) || key];
+    
+    
+    if (projectKey && Object.keys(projectKey).length > 0) {
+      const project = Object.keys(projectKey)[0];
       return this.projects[project].blocks;
     }
 
@@ -302,7 +304,7 @@ export default class Workspace {
       const formatted = new Project(name, projectPath, this.currency, this.blockTemplate);
       for (const resource of project.breakdown.resources) {
         for (const call of resource.metadata.calls) {
-          const filename = path.resolve(cleanFilename(call.filename));
+          const filename = cleanFilename(path.resolve(call.filename));
           logger.debug(`adding file: ${filename} to project: ${projectPath}`);
 
           formatted.setBlock(filename, call.blockName, call.startLine).resources.push(resource);
@@ -327,10 +329,11 @@ export default class Workspace {
   }
 
   private addProjectToFile(filename: string, projectPath: string) {
-    if (this.filesToProjects[filename] === undefined) {
-      this.filesToProjects[filename] = {};
+    const key = filename.split(path.sep).join('/');
+    if (this.filesToProjects[key] === undefined) {
+      this.filesToProjects[key] = {};
     }
 
-    this.filesToProjects[filename][projectPath] = true;
+    this.filesToProjects[key][projectPath] = true;
   }
 }