A polyaldimine of the formula (I) with advantageous properties in use as latent hardener for compositions including isocyanate groups, and compositions containing the polyaldimine of the formula (I) and at least one polyisocyanate and/or at least one polyurethane polymer containing isocyanate groups. The polyaldimine of the formula (I) is odourless, pH-neutral, liquid at room temperature, has low viscosity, has little sensitivity to heat and moisture, and is stable in storage together with isocyanates. It can provide odourless single-component polyurethane compositions which have good stability in storage and which do not produce bubbles when hardened in the presence of moisture, and which cause no problematic odour emissions, giving a hardened elastic material with good mechanical properties and surprisingly little tendency towards plasticizer migration.