diff --git a/pkg/dagger.io/dagger/image.cue b/pkg/dagger.io/dagger/image.cue
index d77efe2e..052d6f43 100644
--- a/pkg/dagger.io/dagger/image.cue
+++ b/pkg/dagger.io/dagger/image.cue
@@ -58,7 +58,7 @@ import (
 	test?: [...string]
 	interval?:    int
 	timeout?:     int
-	startPeriod?: int
+	startperiod?: int
 	retries?:     int
 }
 
diff --git a/plan/task/imageconfig.go b/plan/task/imageconfig.go
index 6a0101dc..a953f299 100644
--- a/plan/task/imageconfig.go
+++ b/plan/task/imageconfig.go
@@ -62,7 +62,7 @@ type HealthConfig struct {
 	// Zero means to inherit. Durations are expressed as integer nanoseconds.
 	Interval    time.Duration `json:"interval,omitempty"`    // Interval is the time to wait between checks.
 	Timeout     time.Duration `json:"timeout,omitempty"`     // Timeout is the time to wait before considering the check to have hung.
-	StartPeriod time.Duration `json:"startPeriod,omitempty"` // The start period for the container to initialize before the retries starts to count down.
+	StartPeriod time.Duration `json:"startperiod,omitempty"` // The start period for the container to initialize before the retries starts to count down.
 
 	// Retries is the number of consecutive failures needed to consider a container as unhealthy.
 	// Zero means inherit.