diff --git a/CHANGELOG.md b/CHANGELOG.md
index 89c0c539b..68857b46b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Add `CiliumNetworkPolicy` for all created Prometheuses.
+- Always set `shards` to 1 for all created Prometheuses.
 
 ## [4.64.0] - 2024-01-19
 
diff --git a/service/controller/resource/monitoring/prometheus/resource.go b/service/controller/resource/monitoring/prometheus/resource.go
index 4256cbbf2..a8720b06f 100644
--- a/service/controller/resource/monitoring/prometheus/resource.go
+++ b/service/controller/resource/monitoring/prometheus/resource.go
@@ -115,6 +115,7 @@ func toPrometheus(ctx context.Context, v interface{}, config Config) (metav1.Obj
 	// Prometheus default image runs using the nobody user (65534)
 	var gid int64 = 65534
 	var walCompression bool = true
+	var prometheusShards int32 = 1
 
 	annotationValue := cluster.GetAnnotations()[key.PrometheusVolumeSizeAnnotation]
 	volumeSize := pvcresizing.PrometheusVolumeSize(annotationValue)
@@ -229,6 +230,7 @@ func toPrometheus(ctx context.Context, v interface{}, config Config) (metav1.Obj
 						Type: corev1.SeccompProfileTypeRuntimeDefault,
 					},
 				},
+				Shards:  &prometheusShards,
 				Storage: &storage,
 				TopologySpreadConstraints: []corev1.TopologySpreadConstraint{
 					{
diff --git a/service/controller/resource/monitoring/prometheus/test/case-1-vintage-mc.golden b/service/controller/resource/monitoring/prometheus/test/case-1-vintage-mc.golden
index a59b6a2d0..bcb1d8af1 100644
--- a/service/controller/resource/monitoring/prometheus/test/case-1-vintage-mc.golden
+++ b/service/controller/resource/monitoring/prometheus/test/case-1-vintage-mc.golden
@@ -98,6 +98,7 @@ spec:
     matchExpressions:
     - key: application.giantswarm.io/team
       operator: DoesNotExist
+  shards: 1
   storage:
     volumeClaimTemplate:
       metadata: {}
diff --git a/service/controller/resource/monitoring/prometheus/test/case-2-aws-v16.golden b/service/controller/resource/monitoring/prometheus/test/case-2-aws-v16.golden
index 481f7c7b8..897f949b0 100644
--- a/service/controller/resource/monitoring/prometheus/test/case-2-aws-v16.golden
+++ b/service/controller/resource/monitoring/prometheus/test/case-2-aws-v16.golden
@@ -95,6 +95,7 @@ spec:
     matchExpressions:
     - key: nonexistentkey
       operator: Exists
+  shards: 1
   storage:
     volumeClaimTemplate:
       metadata: {}
diff --git a/service/controller/resource/monitoring/prometheus/test/case-3-aws-v18.golden b/service/controller/resource/monitoring/prometheus/test/case-3-aws-v18.golden
index 93d77c0b8..e8d71a8db 100644
--- a/service/controller/resource/monitoring/prometheus/test/case-3-aws-v18.golden
+++ b/service/controller/resource/monitoring/prometheus/test/case-3-aws-v18.golden
@@ -95,6 +95,7 @@ spec:
     matchExpressions:
     - key: nonexistentkey
       operator: Exists
+  shards: 1
   storage:
     volumeClaimTemplate:
       metadata: {}
diff --git a/service/controller/resource/monitoring/prometheus/test/case-4-azure-v18.golden b/service/controller/resource/monitoring/prometheus/test/case-4-azure-v18.golden
index 0816b5d40..bffd38f22 100644
--- a/service/controller/resource/monitoring/prometheus/test/case-4-azure-v18.golden
+++ b/service/controller/resource/monitoring/prometheus/test/case-4-azure-v18.golden
@@ -95,6 +95,7 @@ spec:
     matchExpressions:
     - key: nonexistentkey
       operator: Exists
+  shards: 1
   storage:
     volumeClaimTemplate:
       metadata: {}
diff --git a/service/controller/resource/monitoring/prometheus/test/case-5-eks-v18.golden b/service/controller/resource/monitoring/prometheus/test/case-5-eks-v18.golden
index 7460d9e76..1d6f14556 100644
--- a/service/controller/resource/monitoring/prometheus/test/case-5-eks-v18.golden
+++ b/service/controller/resource/monitoring/prometheus/test/case-5-eks-v18.golden
@@ -95,6 +95,7 @@ spec:
     matchExpressions:
     - key: nonexistentkey
       operator: Exists
+  shards: 1
   storage:
     volumeClaimTemplate:
       metadata: {}