diff --git a/.circleci/config.yml b/.circleci/config.yml
index fcad864e97..42cc39dad0 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -11,7 +11,7 @@ executors:
   # should also be updated.
   golang:
     docker:
-    - image: circleci/golang:1.14-node
+    - image: circleci/golang:1.15-node
 
   fuzzit:
     docker:
diff --git a/.promu.yml b/.promu.yml
index cf5acb2499..caaa63a55d 100644
--- a/.promu.yml
+++ b/.promu.yml
@@ -1,7 +1,7 @@
 go:
     # Whenever the Go version is updated here,
     # .circle/config.yml should also be updated.
-    version: 1.14
+    version: 1.15
 repository:
     path: github.com/prometheus/prometheus
 build:
@@ -30,7 +30,6 @@ crossbuild:
         - linux/amd64
         - linux/386
         - darwin/amd64
-        - darwin/386
         - windows/amd64
         - windows/386
         - freebsd/amd64