diff --git a/.github/fly-wsproxies/paris-coder.toml b/.github/fly-wsproxies/paris-coder.toml
index 95a47c2cd60e8..1b33fc2463114 100644
--- a/.github/fly-wsproxies/paris-coder.toml
+++ b/.github/fly-wsproxies/paris-coder.toml
@@ -2,7 +2,7 @@ app = "paris-coder"
 primary_region = "cdg"
 
 [experimental]
-  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://${FLY_PRIVATE_IP}:3000\" /opt/coder wsproxy server"]
+  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://[${FLY_PRIVATE_IP}]:3000\" /opt/coder wsproxy server"]
   auto_rollback = true
 
 [build]
diff --git a/.github/fly-wsproxies/sao-paulo-coder.toml b/.github/fly-wsproxies/sao-paulo-coder.toml
index 39049725e7ba5..c3b614e3e3ed4 100644
--- a/.github/fly-wsproxies/sao-paulo-coder.toml
+++ b/.github/fly-wsproxies/sao-paulo-coder.toml
@@ -2,7 +2,7 @@ app = "sao-paulo-coder"
 primary_region = "gru"
 
 [experimental]
-  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://${FLY_PRIVATE_IP}:3000\" /opt/coder wsproxy server"]
+  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://[${FLY_PRIVATE_IP}]:3000\" /opt/coder wsproxy server"]
   auto_rollback = true
 
 [build]
diff --git a/.github/fly-wsproxies/sydney-coder.toml b/.github/fly-wsproxies/sydney-coder.toml
index 5e73bef59f546..98798f188df73 100644
--- a/.github/fly-wsproxies/sydney-coder.toml
+++ b/.github/fly-wsproxies/sydney-coder.toml
@@ -2,7 +2,7 @@ app = "sydney-coder"
 primary_region = "syd"
 
 [experimental]
-  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://${FLY_PRIVATE_IP}:3000\" /opt/coder wsproxy server"]
+  entrypoint = ["/bin/sh", "-c", "CODER_DERP_SERVER_RELAY_URL=\"http://[${FLY_PRIVATE_IP}]:3000\" /opt/coder wsproxy server"]
   auto_rollback = true
 
 [build]