diff --git a/src/common/config/configOverrides.ts b/src/common/config/configOverrides.ts
index 69452a79..493882e2 100644
--- a/src/common/config/configOverrides.ts
+++ b/src/common/config/configOverrides.ts
@@ -118,7 +118,13 @@ function parseConfigValue(key: keyof typeof UserConfigSchema.shape, value: unkno
         throw new Error(`Invalid config key: ${key}`);
     }
 
-    return fieldSchema.safeParse(value).data;
+    const result = fieldSchema.safeParse(value);
+    if (!result.success) {
+        throw new Error(
+            `Invalid configuration for the following fields:\n${result.error.issues.map((issue) => `${key} - ${issue.message}`).join("\n")}`
+        );
+    }
+    return result.data;
 }
 
 /**
diff --git a/tests/unit/common/config/configOverrides.test.ts b/tests/unit/common/config/configOverrides.test.ts
index 01a4256c..0381f5a2 100644
--- a/tests/unit/common/config/configOverrides.test.ts
+++ b/tests/unit/common/config/configOverrides.test.ts
@@ -185,7 +185,6 @@ describe("configOverrides", () => {
                     headers: {
                         "x-mongodb-mcp-disabled-tools": "tool2",
                         "x-mongodb-mcp-confirmation-required-tools": "drop-collection",
-                        "x-mongodb-mcp-preview-features": "feature1",
                     },
                 };
                 const result = applyConfigOverrides({ baseConfig: baseConfig as UserConfig, request });
@@ -403,14 +402,15 @@ describe("configOverrides", () => {
         });
 
         describe("edge cases", () => {
-            it("should handle invalid numeric values gracefully", () => {
+            it("should error with values which do not match the schema", () => {
                 const request: RequestContext = {
                     headers: {
                         "x-mongodb-mcp-idle-timeout-ms": "not-a-number",
                     },
                 };
-                const result = applyConfigOverrides({ baseConfig: baseConfig as UserConfig, request });
-                expect(result.idleTimeoutMs).toBe(baseConfig.idleTimeoutMs);
+                expect(() => applyConfigOverrides({ baseConfig: baseConfig as UserConfig, request })).toThrow(
+                    "Invalid configuration for the following fields:\nidleTimeoutMs - Invalid input: expected number, received NaN"
+                );
             });
 
             it("should handle empty string values for arrays", () => {