diff --git a/deno.json b/deno.json
index 349a16a..0c27868 100644
--- a/deno.json
+++ b/deno.json
@@ -4,10 +4,10 @@
     "include": ["src/", "test/"]
   },
   "imports": {
-    "mysql/": "https://deno.land/x/mysql@v2.12.0/",
+    "mysql/": "https://deno.land/x/mysql@v2.12.1/",
     "postgres/": "https://deno.land/x/postgres@v0.17.0/",
     "sqlite/": "https://deno.land/x/sqlite@v3.8/",
-    "std/": "https://deno.land/std@0.201.0/"
+    "std/": "https://deno.land/std@0.203.0/"
   },
   "tasks": {
     "check": "deno check **/*.ts && deno fmt --check",
diff --git a/src/db.ts b/src/db.ts
index d063b35..5f7e6d9 100644
--- a/src/db.ts
+++ b/src/db.ts
@@ -141,14 +141,15 @@ export class DB {
   }
 
   // Transforms parameters (and SQL) into array-like and references via `?`
-  static _transformParameters(sql: string, objectParameters: { [key: string]: unknown }, arrayParameters: unknown[]): string {
+  static _transformParameters(sql: string, objectParameters: { [key: string]: unknown }, arrayParameters: unknown[], safe?: boolean): string {
     arrayParameters.splice(0, arrayParameters.length);
     return sql.replace(/[:][$A-Z_][0-9A-Z_$]*/ig, function (name) {
       const value = objectParameters[name.substring(1)];
+      if (value === undefined && !safe) throw new Error("Undefined parameter '" + name + "'");
       const isArray = Array.isArray(value);
       // If it is an array we need to repeat N times the '?' and append all the values
       if (isArray) arrayParameters.push(...value);
-      else arrayParameters.push(value ?? undefined);
+      else arrayParameters.push(value);
       return isArray ? value.map((_) => "?").join(",") : "?";
     });
   }