diff --git a/docs/resources/agent.md b/docs/resources/agent.md
index 8c3080d7..a064585c 100644
--- a/docs/resources/agent.md
+++ b/docs/resources/agent.md
@@ -47,7 +47,7 @@ resource "kubernetes_pod" "dev" {
 ### Optional
 
 - `auth` (String) The authentication type the agent will use. Must be one of: "token", "google-instance-identity", "aws-instance-identity", "azure-instance-identity".
-- `connection_timeout` (Number) Time in seconds until the agent is marked as timed out when a connection with the server cannot be established.
+- `connection_timeout` (Number) Time in seconds until the agent is marked as timed out when a connection with the server cannot be established. A value of zero never marks the agent as timed out.
 - `dir` (String) The starting directory when a user creates a shell session. Defaults to $HOME.
 - `env` (Map of String) A mapping of environment variables to set inside the workspace.
 - `motd_file` (String) The path to a file within the workspace containing a message to display to users when they login via SSH. A typical value would be /etc/motd.
diff --git a/provider/agent.go b/provider/agent.go
index c9d7582c..0216d8dd 100644
--- a/provider/agent.go
+++ b/provider/agent.go
@@ -89,11 +89,12 @@ func agentResource() *schema.Resource {
 				Computed:    true,
 			},
 			"connection_timeout": {
-				Type:        schema.TypeInt,
-				Default:     120,
-				ForceNew:    true,
-				Optional:    true,
-				Description: "Time in seconds until the agent is marked as timed out when a connection with the server cannot be established.",
+				Type:         schema.TypeInt,
+				Default:      120,
+				ForceNew:     true,
+				Optional:     true,
+				Description:  "Time in seconds until the agent is marked as timed out when a connection with the server cannot be established. A value of zero never marks the agent as timed out.",
+				ValidateFunc: validation.IntAtLeast(0),
 			},
 			"troubleshooting_url": {
 				Type:        schema.TypeString,