diff --git a/deployments/kubernetes/chart/reloader/templates/deployment.yaml b/deployments/kubernetes/chart/reloader/templates/deployment.yaml
index 2aff3e5a0..31ab80895 100644
--- a/deployments/kubernetes/chart/reloader/templates/deployment.yaml
+++ b/deployments/kubernetes/chart/reloader/templates/deployment.yaml
@@ -225,7 +225,7 @@ spec:
           - "--resources-to-ignore=secrets"
           {{- end }}
           {{- if .Values.reloader.ignoreConfigMaps }}
-          - "--resources-to-ignore=configMaps"
+          - "--resources-to-ignore=configmaps"
           {{- end }}
           {{- if and (.Values.reloader.ignoreJobs) (.Values.reloader.ignoreCronJobs) }}
           - "--ignored-workload-types=jobs,cronjobs"
diff --git a/internal/pkg/util/util.go b/internal/pkg/util/util.go
index 2b961f0d3..365d35c39 100644
--- a/internal/pkg/util/util.go
+++ b/internal/pkg/util/util.go
@@ -94,7 +94,7 @@ func ConfigureReloaderFlags(cmd *cobra.Command) {
 	cmd.PersistentFlags().StringVar(&options.LogFormat, "log-format", "", "Log format to use (empty string for text, or JSON)")
 	cmd.PersistentFlags().StringVar(&options.LogLevel, "log-level", "info", "Log level to use (trace, debug, info, warning, error, fatal and panic)")
 	cmd.PersistentFlags().StringVar(&options.WebhookUrl, "webhook-url", "", "webhook to trigger instead of performing a reload")
-	cmd.PersistentFlags().StringSliceVar(&options.ResourcesToIgnore, "resources-to-ignore", options.ResourcesToIgnore, "list of resources to ignore (valid options 'configMaps' or 'secrets')")
+	cmd.PersistentFlags().StringSliceVar(&options.ResourcesToIgnore, "resources-to-ignore", options.ResourcesToIgnore, "list of resources to ignore (valid options 'configmaps' or 'secrets')")
 	cmd.PersistentFlags().StringSliceVar(&options.WorkloadTypesToIgnore, "ignored-workload-types", options.WorkloadTypesToIgnore, "list of workload types to ignore (valid options: 'jobs', 'cronjobs', or both)")
 	cmd.PersistentFlags().StringSliceVar(&options.NamespacesToIgnore, "namespaces-to-ignore", options.NamespacesToIgnore, "list of namespaces to ignore")
 	cmd.PersistentFlags().StringSliceVar(&options.NamespaceSelectors, "namespace-selector", options.NamespaceSelectors, "list of key:value labels to filter on for namespaces")
@@ -114,17 +114,26 @@ func GetIgnoredResourcesList() (List, error) {
 
 	ignoredResourcesList := options.ResourcesToIgnore // getStringSliceFromFlags(cmd, "resources-to-ignore")
 
+	// Normalize to the canonical lowercase keys used in kube.ResourceMap so the
+	// comparison is case-insensitive (e.g. "configMaps", "ConfigMaps", "sEcrets"
+	// all map to their canonical lowercase form).
+	normalized := make(List, 0, len(ignoredResourcesList))
 	for _, v := range ignoredResourcesList {
-		if v != "configMaps" && v != "secrets" {
-			return nil, fmt.Errorf("'resources-to-ignore' only accepts 'configMaps' or 'secrets', not '%s'", v)
+		switch strings.ToLower(v) {
+		case "configmaps":
+			normalized = append(normalized, "configmaps")
+		case "secrets":
+			normalized = append(normalized, "secrets")
+		default:
+			return nil, fmt.Errorf("'resources-to-ignore' only accepts 'configmaps' or 'secrets', not '%s'", v)
 		}
 	}
 
-	if len(ignoredResourcesList) > 1 {
-		return nil, errors.New("'resources-to-ignore' only accepts 'configMaps' or 'secrets', not both")
+	if len(normalized) > 1 {
+		return nil, errors.New("'resources-to-ignore' only accepts 'configmaps' or 'secrets', not both")
 	}
 
-	return ignoredResourcesList, nil
+	return normalized, nil
 }
 
 func GetIgnoredWorkloadTypesList() (List, error) {
diff --git a/internal/pkg/util/util_test.go b/internal/pkg/util/util_test.go
index 338f329f3..31c82c416 100644
--- a/internal/pkg/util/util_test.go
+++ b/internal/pkg/util/util_test.go
@@ -136,6 +136,97 @@ func TestGetIgnoredWorkloadTypesList(t *testing.T) {
 	}
 }
 
+func TestGetIgnoredResourcesList(t *testing.T) {
+	// Save original state
+	originalResources := options.ResourcesToIgnore
+	defer func() {
+		options.ResourcesToIgnore = originalResources
+	}()
+
+	tests := []struct {
+		name        string
+		resources   []string
+		expectError bool
+		expected    []string
+	}{
+		{
+			name:        "Lowercase configmaps (canonical) normalizes to configmaps",
+			resources:   []string{"configmaps"},
+			expectError: false,
+			expected:    []string{"configmaps"},
+		},
+		{
+			name:        "Legacy camelCase configMaps normalizes to configmaps",
+			resources:   []string{"configMaps"},
+			expectError: false,
+			expected:    []string{"configmaps"},
+		},
+		{
+			name:        "Mixed-case ConfigMaps normalizes to configmaps",
+			resources:   []string{"ConfigMaps"},
+			expectError: false,
+			expected:    []string{"configmaps"},
+		},
+		{
+			name:        "secrets",
+			resources:   []string{"secrets"},
+			expectError: false,
+			expected:    []string{"secrets"},
+		},
+		{
+			name:        "Mixed-case sEcrets normalizes to secrets",
+			resources:   []string{"sEcrets"},
+			expectError: false,
+			expected:    []string{"secrets"},
+		},
+		{
+			name:        "Empty list",
+			resources:   []string{},
+			expectError: false,
+			expected:    []string{},
+		},
+		{
+			name:        "Invalid resource",
+			resources:   []string{"deployments"},
+			expectError: true,
+			expected:    nil,
+		},
+		{
+			name:        "Both configmaps and secrets rejected",
+			resources:   []string{"configmaps", "secrets"},
+			expectError: true,
+			expected:    nil,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			options.ResourcesToIgnore = tt.resources
+			result, err := GetIgnoredResourcesList()
+
+			if tt.expectError && err == nil {
+				t.Errorf("Expected error but got none")
+			}
+			if !tt.expectError && err != nil {
+				t.Errorf("Expected no error but got: %v", err)
+			}
+
+			if !tt.expectError {
+				if len(result) != len(tt.expected) {
+					t.Errorf("Expected %v, got %v", tt.expected, result)
+					return
+				}
+				for i, expected := range tt.expected {
+					if result[i] != expected {
+						t.Errorf("Expected %v, got %v", tt.expected, result)
+						break
+					}
+				}
+			}
+		})
+	}
+}
+
 func TestListContains(t *testing.T) {
 	tests := []struct {
 		name     string