diff --git a/modules/lang/scala/packages.el b/modules/lang/scala/packages.el
index cc85e38ea..93c1f879e 100644
--- a/modules/lang/scala/packages.el
+++ b/modules/lang/scala/packages.el
@@ -5,4 +5,7 @@
 (package! scala-mode)
 
 (unless (featurep! +lsp)
-  (package! ensime))
+  ;; Fix #1697: Ensime doesn't have a master branch and its MELPA recipe doesn't
+  ;; specify a branch. Straight can't handle packages with non-standard primary
+  ;; branches (at the time of writing), so we must specify it manually:
+  (package! ensime :recipe (:branch "2.0")))