diff --git a/packages/visualizations/src/components/Map/utils.ts b/packages/visualizations/src/components/Map/utils.ts
index 5b8850b2..faef7126 100644
--- a/packages/visualizations/src/components/Map/utils.ts
+++ b/packages/visualizations/src/components/Map/utils.ts
@@ -6,8 +6,14 @@ import type { Feature, FeatureCollection, Position, BBox } from 'geojson';
 import type { Scale } from 'chroma-js';
 import { DEFAULT_COLORS } from './constants';
 import { assertUnreachable } from '../utils';
-import { ColorScaleTypes } from '../types';
-import type { Color, ColorScale, DataBounds } from '../types';
+import {
+    Color,
+    ColorScale,
+    DataBounds,
+    isGroupByForMatchExpression,
+    ColorScaleTypes,
+} from '../types';
+
 import type {
     ChoroplethDataValue,
     ChoroplethFixedTooltipDescription,
@@ -296,9 +302,8 @@ export const computeMatchExpression = (
     const groupByColors: ExpressionInputType[] = [];
     Object.entries(colors).forEach((e) => groupByColors.push(...e));
     groupByColors.push(emptyValueColor); // Default fallback color
-    // We constructed a match expression so we can cast here the final type
-    return [
-        ...matchExpression,
-        ...(groupByColors as [ExpressionInputType, ExpressionInputType, ExpressionInputType]),
-    ];
+    if (!isGroupByForMatchExpression(groupByColors)) {
+        throw new Error('Not the expected type for complete match expression');
+    }
+    return [...matchExpression, ...groupByColors];
 };
diff --git a/packages/visualizations/src/components/MapPoi/utils.ts b/packages/visualizations/src/components/MapPoi/utils.ts
index ec5c6329..2c133bd5 100644
--- a/packages/visualizations/src/components/MapPoi/utils.ts
+++ b/packages/visualizations/src/components/MapPoi/utils.ts
@@ -6,7 +6,7 @@ import type {
     ExpressionInputType,
 } from 'maplibre-gl';
 
-import type { Color } from '../types';
+import { isGroupByForMatchExpression, type Color } from '../types';
 
 import type {
     CenterZoomOptions,
@@ -55,13 +55,12 @@ export const getMapLayers = (layers?: Layer[]): CircleLayerSpecification[] => {
                 groupByColors.push(color, colors[color]);
             });
             groupByColors.push(layerColor);
+            if (!isGroupByForMatchExpression(groupByColors)) {
+                throw new Error('Not the expected type for complete match expression');
+            }
             circleColor = [
                 ...matchExpression,
-                ...(groupByColors as [
-                    ExpressionInputType,
-                    ExpressionInputType,
-                    ExpressionInputType
-                ]),
+                ...groupByColors,
             ];
 
             if (borderColors) {
@@ -74,14 +73,12 @@ export const getMapLayers = (layers?: Layer[]): CircleLayerSpecification[] => {
                     groupByBorderColors.push(borderColor, borderColors[borderColor]);
                 });
                 groupByBorderColors.push(circleBorderColor || DEFAULT_DARK_GREY);
-                // We constructed a match expression so we can cast here the final type
+                if (!isGroupByForMatchExpression(groupByBorderColors)) {
+                    throw new Error('Not the expected type for complete match expression');
+                }
                 circleBorderColor = [
                     ...matchBorderExpression,
-                    ...(groupByBorderColors as [
-                        ExpressionInputType,
-                        ExpressionInputType,
-                        ExpressionInputType
-                    ]),
+                    ...groupByBorderColors,
                 ];
             }
         }
diff --git a/packages/visualizations/src/components/types.ts b/packages/visualizations/src/components/types.ts
index c6f87b1d..2e1f0cfc 100644
--- a/packages/visualizations/src/components/types.ts
+++ b/packages/visualizations/src/components/types.ts
@@ -1,3 +1,5 @@
+import type { ExpressionInputType } from 'maplibre-gl';
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 export type DataFrame = Record<string, any>[];
 
@@ -33,3 +35,10 @@ export type PaletteScale = {
 };
 
 export type ColorScale = GradientScale | PaletteScale;
+
+// We expect an array with couples of values and ExpressionInput and for the last element a default ExpressionInput
+export function isGroupByForMatchExpression(
+    value: ExpressionInputType[]
+): value is [ExpressionInputType, ExpressionInputType, ExpressionInputType] {
+    return value.length >= 3 && value.length % 2 === 1;
+}