diff --git a/src/file-actions.js b/src/file-actions.js
index 4c33583821..76317a3df9 100644
--- a/src/file-actions.js
+++ b/src/file-actions.js
@@ -23,10 +23,15 @@ const openPdf = new FileAction({
 			{ productName: getCapabilities().productName })
 	},
 
-	enabled: () => {
+	enabled: (files) => {
+		if (files.length !== 1) {
+			return false
+		}
+
+		const isPdf = files[0].mime === 'application/pdf'
 		// Only enable the file action when files_pdfviewer is enabled
 		const optionalMimetypes = getCapabilities().mimetypesNoDefaultOpen
-		return optionalMimetypes.includes('application/pdf')
+		return isPdf && optionalMimetypes.includes('application/pdf')
 	},
 
 	exec: (file) => {