diff --git a/formats/aci.py b/formats/aci.py
index dc1029d68..421b6bcfa 100644
--- a/formats/aci.py
+++ b/formats/aci.py
@@ -177,6 +177,17 @@ class ACIImage(TarImageFormatter):
     hostname = app.config['SERVER_HOSTNAME']
     hostname = hostname.split(':', 1)[0]
 
+    # Calculate the environment variables.
+    docker_env_vars = config.get('Env', [])
+    env_vars = []
+    for var in docker_env_vars:
+      pieces = var.split('=')
+      if len(pieces) != 2:
+        continue
+
+      env_vars.append(pieces)
+
+
     manifest = {
       "acKind": "ImageManifest",
       "acVersion": "0.6.1",
@@ -202,8 +213,7 @@ class ACIImage(TarImageFormatter):
         "group": config.get('Group', '') or 'root',
         "eventHandlers": [],
         "workingDirectory": config.get('WorkingDir', '') or '/',
-        "environment": [{"name": key, "value": value}
-                        for (key, value) in [e.split('=') for e in config.get('Env', []) or []]],
+        "environment": [{"name": key, "value": value} for (key, value) in env_vars],
         "isolators": ACIImage._build_isolators(config),
         "mountPoints": ACIImage._build_volumes(config),
         "ports": ACIImage._build_ports(config),