diff --git a/.changelog/777.txt b/.changelog/777.txt
new file mode 100644
index 000000000..5018394d2
--- /dev/null
+++ b/.changelog/777.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+resource/deployment: Fix issue setting the elasticsearch_username when resetting the elasticsearch_password
+```
diff --git a/ec/ecresource/deploymentresource/deployment/v2/schema.go b/ec/ecresource/deploymentresource/deployment/v2/schema.go
index 943472790..4fb1820b1 100644
--- a/ec/ecresource/deploymentresource/deployment/v2/schema.go
+++ b/ec/ecresource/deploymentresource/deployment/v2/schema.go
@@ -90,6 +90,7 @@ func DeploymentSchema() schema.Schema {
 				Computed:    true,
 				PlanModifiers: []planmodifier.String{
 					stringplanmodifier.UseStateForUnknown(),
+					setUnknownIfResetPasswordIsTrue{},
 				},
 			},
 			"elasticsearch_password": schema.StringAttribute{