diff --git a/xpcom/build/BinaryPath.h b/xpcom/build/BinaryPath.h
index a6c86191947..c2a072aff9e 100644
--- a/xpcom/build/BinaryPath.h
+++ b/xpcom/build/BinaryPath.h
@@ -56,9 +56,8 @@ private:
       return NS_ERROR_FAILURE;
     }
 
-    UInt8 tempBuffer[MAXPATHLEN];
     nsresult rv;
-    if (CFURLGetFileSystemRepresentation(executableURL, false, tempBuffer,
+    if (CFURLGetFileSystemRepresentation(executableURL, false, (UInt8*)aResult,
                                          MAXPATHLEN)) {
       rv = NS_OK;
     } else {
@@ -69,11 +68,11 @@ private:
     // for example.
     size_t readPos = 0;
     size_t writePos = 0;
-    while (tempBuffer[readPos] != '\0') {
-      if (tempBuffer[readPos] == '.' && tempBuffer[readPos + 1] == '/') {
+    while (aResult[readPos] != '\0') {
+      if (aResult[readPos] == '.' && aResult[readPos + 1] == '/') {
         readPos += 2;
       }
-      aResult[writePos] = tempBuffer[readPos];
+      aResult[writePos] = aResult[readPos];
       readPos++;
       writePos++;
     }