diff --git a/src/pdb.ts b/src/pdb.ts
index c5f8359..6bcddd4 100644
--- a/src/pdb.ts
+++ b/src/pdb.ts
@@ -33,7 +33,7 @@ export class PdbFile {
         }
 
         let fileHandle: FileHandle;
-
+        let pdbFile: PdbFile;
         try {
             fileHandle = await open(pdbFilePath, 'r');
 
@@ -69,10 +69,12 @@ export class PdbFile {
             } 
             
             const guid = new PdbGuid(guid_d1, guid_d2, guid_d3, guid_d4, age);
-            return new PdbFile(guid);
+            pdbFile = new PdbFile(guid);
         } finally {
             await fileHandle!?.close();
         }
+
+        return pdbFile;
     }
 
     private static async getGuidBytesFromPdbStream(root: PdbRootStream, fileHandle: FileHandle): Promise<Uint8Array> {
diff --git a/src/pe.ts b/src/pe.ts
index d35af12..74a5cfa 100644
--- a/src/pe.ts
+++ b/src/pe.ts
@@ -32,7 +32,7 @@ export class PeFile {
         }
 
         let fileHandle: FileHandle;
-
+        let peFile: PeFile;
         try {
             fileHandle = await open(peFilePath, 'r');
 
@@ -62,9 +62,11 @@ export class PeFile {
             }
             
             const guid = new PeGuid(timeStamp, sizeOfImage);
-            return new PeFile(guid);
+            peFile = new PeFile(guid);
         } finally {
             await fileHandle!?.close();
         }
+
+        return peFile;
     }
 }
diff --git a/src/root.ts b/src/root.ts
index accf51c..5660565 100644
--- a/src/root.ts
+++ b/src/root.ts
@@ -50,7 +50,7 @@ export class PdbRootStream {
         return uints;
     }
 
-    static async createFromFile(filePath: string): Promise<PdbRootStream | null> {
+    static async createFromFile(filePath: string): Promise<PdbRootStream> {
         // LLVM.org refers to the first section of the file as The Superblock
         // At file offset 0 in an MSF file is the MSF SuperBlock, which is laid out as follows:
         //
@@ -64,6 +64,7 @@ export class PdbRootStream {
         //  ulittle32_t BlockMapAddr;
         // };
         let fileHandle: FileHandle;
+        let pdbRootStream: PdbRootStream;
         try {
             const fileHandle = await open(filePath, 'r');
 
@@ -122,10 +123,12 @@ export class PdbRootStream {
                 streamDirectory[i] = getStreamBytesAsNumber(rootPageData, i);
             }
 
-            return new PdbRootStream(blockSize, directoryBytesLength, streamDirectory);
+            pdbRootStream = new PdbRootStream(blockSize, directoryBytesLength, streamDirectory);
         } finally {
             fileHandle!?.close();
         }
+
+        return pdbRootStream;
     }
 }