diff --git a/stack-lts6.yaml b/stack-lts6.yaml
index f4bbb7c81..e126d98f6 100644
--- a/stack-lts6.yaml
+++ b/stack-lts6.yaml
@@ -1,4 +1,4 @@
-resolver: lts-6.17
+resolver: lts-6.27
 packages:
 - '.'
 extra-deps:
diff --git a/stack-lts7.yaml b/stack-lts7.yaml
index 92a1898c3..5a4ec71ea 100644
--- a/stack-lts7.yaml
+++ b/stack-lts7.yaml
@@ -1,4 +1,4 @@
-resolver: lts-7.0
+resolver: lts-7.14
 packages:
 - '.'
 flags:
diff --git a/stack-nightly.yaml b/stack-nightly.yaml
index 81dc768dc..897c5794e 100644
--- a/stack-nightly.yaml
+++ b/stack-nightly.yaml
@@ -1,4 +1,4 @@
-resolver: nightly-2016-09-15
+resolver: nightly-2016-12-22
 packages:
 - '.'
 flags: