diff --git a/provider/lib.go b/provider/lib.go
index 818e2d7..ddcc17b 100644
--- a/provider/lib.go
+++ b/provider/lib.go
@@ -505,10 +505,17 @@ var siteImporter = schema.ResourceImporter{
 }
 
 func validateConditionField(val interface{}, key string) ([]string, []error) {
-	if existsInString(val.(string), "scheme", "method", "path", "useragent", "domain", "ip", "responseCode", "agentname", "paramname", "paramvalue", "country", "name", "valueString", "valueIp", "signalType", "signal", "requestHeader", "queryParameter", "postParameter") {
+	knownFields := []string{
+		"scheme", "method", "path", "useragent", "domain", "ip", "responseCode", "agentname",
+		"paramname", "paramvalue", "country", "name", "valueString", "valueIp", "signalType",
+		"signal", "requestHeader", "queryParameter", "postParameter", "requestCookie", "value",
+	}
+
+	if existsInString(val.(string), knownFields...) {
 		return nil, nil
 	}
-	return []string{fmt.Sprintf("received '%s' for conditions.field. This is not necessairly an error, but we only know about the following values. If this is a new value, please open a PR to get it added.\n(scheme, method, path, useragent, domain, ip, responseCode, agentname, paramname, paramvalue, country, name, valueString, valueIp, signalType, signal, requestHeader, queryParameter, postParameter)", val.(string))}, nil
+
+	return []string{fmt.Sprintf("received %q for conditions.field. This is not necessarily an error, but we only know about the following values. If this is a new value, please open a PR to get it added.\n(%s)", val.(string), strings.Join(knownFields, ", "))}, nil
 }
 
 func validateActionResponseCode(val interface{}, key string) ([]string, []error) {
diff --git a/provider/lib_test.go b/provider/lib_test.go
index 17c7151..9a4971b 100644
--- a/provider/lib_test.go
+++ b/provider/lib_test.go
@@ -124,3 +124,31 @@ func testInspect() resource.TestCheckFunc {
 	}
 }
 */
+
+func TestValidateConditionField(t *testing.T) {
+	cases := []struct {
+		in      string
+		wantErr bool
+	}{
+		{in: "scheme"},
+		{in: "queryParameter"},
+		{in: "value"},
+
+		{in: "unknownconditionfield", wantErr: true},
+	}
+
+	for _, tt := range cases {
+		got, err := validateConditionField(tt.in, "key")
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		if got != nil && !tt.wantErr {
+			t.Errorf("validateConditionField(%q) returned invalid, want valid", tt.in)
+		}
+
+		if got == nil && tt.wantErr {
+			t.Errorf("validateConditionField(%q) returned valid, want invalid", tt.in)
+		}
+	}
+}