diff --git a/pkg/koyeb/sandbox_create.go b/pkg/koyeb/sandbox_create.go
index c6b52ea7..a57d511a 100644
--- a/pkg/koyeb/sandbox_create.go
+++ b/pkg/koyeb/sandbox_create.go
@@ -163,6 +163,35 @@ func parseSandboxDefinitionFlags(ctx *CLIContext, cmd *cobra.Command, def *koyeb
 		}
 	}
 
+	// Require at least one sleep delay when min-scale is 0 and the user explicitly
+	// changed either the scale or sleep delay flags.
+	sleepChanged := flags.Lookup("light-sleep-delay").Changed || flags.Lookup("deep-sleep-delay").Changed
+	if minScale == 0 && (flags.Lookup("min-scale").Changed || sleepChanged) {
+		hasSleepTarget := false
+		for _, target := range scaling.GetTargets() {
+			if target.HasSleepIdleDelay() {
+				sid := target.GetSleepIdleDelay()
+				if (sid.LightSleepValue != nil && *sid.LightSleepValue > 0) ||
+					(sid.DeepSleepValue != nil && *sid.DeepSleepValue > 0) {
+					hasSleepTarget = true
+					break
+				}
+			}
+		}
+		if !hasSleepTarget {
+			return &errors.CLIError{
+				What: "Error while configuring the sandbox",
+				Why:  "setting min-scale to 0 requires a sleep delay policy",
+				Additional: []string{
+					"When min-scale is 0, a sleep delay must be configured to define when the service scales to zero.",
+					"Use --light-sleep-delay and/or --deep-sleep-delay to set the sleep policy.",
+				},
+				Orig:     nil,
+				Solution: "Add --light-sleep-delay <duration> and/or --deep-sleep-delay <duration> to your command and try again",
+			}
+		}
+	}
+
 	def.SetScalings([]koyeb.DeploymentScaling{*scaling})
 
 	return nil
diff --git a/pkg/koyeb/services.go b/pkg/koyeb/services.go
index 94891fb3..99a35e95 100644
--- a/pkg/koyeb/services.go
+++ b/pkg/koyeb/services.go
@@ -1367,8 +1367,8 @@ func (h *ServiceHandler) setScalingsTargets(flags *pflag.FlagSet, scaling *koyeb
 						sid.DeepSleepValue = nil
 					}
 				}
-				// Remove the target entirely if both values are unset
-				if sid.LightSleepValue == nil && sid.DeepSleepValue == nil {
+				// Remove the target entirely when min-scale is not 0
+				if scaling.GetMin() != 0 {
 					continue
 				}
 				target.SetSleepIdleDelay(sid)
@@ -1396,6 +1396,37 @@ func (h *ServiceHandler) setScalingsTargets(flags *pflag.FlagSet, scaling *koyeb
 		}
 		scaling.Targets = newTargets
 	}
+
+	// Require at least one sleep delay when min-scale is 0 and the user explicitly
+	// changed either the scale or sleep delay flags.
+	scaleChanged := flags.Lookup("min-scale").Changed || flags.Lookup("scale").Changed
+	sleepChanged := flags.Lookup("light-sleep-delay").Changed || flags.Lookup("deep-sleep-delay").Changed
+	if scaling.GetMin() == 0 && (scaleChanged || sleepChanged) {
+		hasSleepTarget := false
+		for _, target := range scaling.GetTargets() {
+			if target.HasSleepIdleDelay() {
+				sid := target.GetSleepIdleDelay()
+				if (sid.LightSleepValue != nil && *sid.LightSleepValue > 0) ||
+					(sid.DeepSleepValue != nil && *sid.DeepSleepValue > 0) {
+					hasSleepTarget = true
+					break
+				}
+			}
+		}
+		if !hasSleepTarget {
+			return &errors.CLIError{
+				What: "Error while configuring the service",
+				Why:  "setting min-scale to 0 requires a sleep delay policy",
+				Additional: []string{
+					"When min-scale is 0, a sleep delay must be configured to define when the service scales to zero.",
+					"Use --light-sleep-delay and/or --deep-sleep-delay to set the sleep policy.",
+				},
+				Orig:     nil,
+				Solution: "Add --light-sleep-delay <duration> and/or --deep-sleep-delay <duration> to your command and try again",
+			}
+		}
+	}
+
 	return nil
 }
 
diff --git a/pkg/koyeb/services_test.go b/pkg/koyeb/services_test.go
index 032bba7b..6de687b0 100644
--- a/pkg/koyeb/services_test.go
+++ b/pkg/koyeb/services_test.go
@@ -551,7 +551,7 @@ func TestSetSleepDelayFlags(t *testing.T) {
 				},
 			},
 		},
-		"disable both sleep delays removes target": {
+		"error when disabling both sleep delays with min-scale zero": {
 			args:     []string{"--light-sleep-delay", "0", "--deep-sleep-delay", "0"},
 			minScale: 0,
 			currentTargets: []koyeb.DeploymentScalingTarget{
@@ -562,7 +562,7 @@ func TestSetSleepDelayFlags(t *testing.T) {
 					},
 				},
 			},
-			expected: []koyeb.DeploymentScalingTarget{},
+			expectedErr: true,
 		},
 		"preserve other targets when setting sleep delay": {
 			args:     []string{"--light-sleep-delay", "5m"},
@@ -620,6 +620,56 @@ func TestSetSleepDelayFlags(t *testing.T) {
 			minScale:    2,
 			expectedErr: true,
 		},
+		"error when min-scale is zero without sleep delays": {
+			args:           []string{"--min-scale", "0"},
+			minScale:       0,
+			currentTargets: nil,
+			expectedErr:    true,
+		},
+		"no error when min-scale is zero with existing sleep target and no flags changed": {
+			args:     []string{},
+			minScale: 0,
+			currentTargets: []koyeb.DeploymentScalingTarget{
+				{
+					SleepIdleDelay: &koyeb.DeploymentScalingTargetSleepIdleDelay{
+						LightSleepValue: koyeb.PtrInt64(300),
+					},
+				},
+			},
+			expected: []koyeb.DeploymentScalingTarget{
+				{
+					SleepIdleDelay: &koyeb.DeploymentScalingTargetSleepIdleDelay{
+						LightSleepValue: koyeb.PtrInt64(300),
+					},
+				},
+			},
+		},
+		"error when disabling deep sleep with zero-value light sleep from API": {
+			args:     []string{"--deep-sleep-delay", "0"},
+			minScale: 0,
+			currentTargets: []koyeb.DeploymentScalingTarget{
+				{
+					SleepIdleDelay: &koyeb.DeploymentScalingTargetSleepIdleDelay{
+						LightSleepValue: koyeb.PtrInt64(0),
+						DeepSleepValue:  koyeb.PtrInt64(60),
+					},
+				},
+			},
+			expectedErr: true,
+		},
+		"error when disabling sleep delay with existing zero values": {
+			args:     []string{"--light-sleep-delay", "0"},
+			minScale: 0,
+			currentTargets: []koyeb.DeploymentScalingTarget{
+				{
+					SleepIdleDelay: &koyeb.DeploymentScalingTargetSleepIdleDelay{
+						LightSleepValue: koyeb.PtrInt64(0),
+						DeepSleepValue:  koyeb.PtrInt64(0),
+					},
+				},
+			},
+			expectedErr: true,
+		},
 	}
 
 	for name, tc := range tests {