--- a/toolkit/mozapps/extensions/internal/XPIInstall.jsm
+++ b/toolkit/mozapps/extensions/internal/XPIInstall.jsm
@@ -1474,16 +1474,17 @@ class AddonInstall {
       return;
     }
 
     try {
       this.logger.debug(
         `removeTemporaryFile: ${this.sourceURI.spec} removing temp file ` +
           this.file.path
       );
+      flushJarCache(this.file);
       this.file.remove(true);
       this.ownsTempFile = false;
     } catch (e) {
       this.logger.warn(
         `Failed to remove temporary file ${this.file.path} for addon ` +
           this.sourceURI.spec,
         e
       );