Abstract: Disruption of the MEKK1‐MKK1/MKK2‐MPK4 kinase cascade leads to activation of immunity mediated by the nucleotide‐binding leucine‐rich repeat (NLR) immune receptor SUMM2, which monitors the phosphorylation status of CRCK3. Here we report that two receptor‐like kinases (RLKs), MDS1, and MDS2, function redundantly to promote SUMM2‐mediated immunity. Activation of SUMM2‐mediated immunity is dependent on MDS1, and to a less extent on MDS2. MDS1 associates with CRCK3 in planta and can phosphorylate CRCK3 in vitro, suggesting that it may target CRCK3 to positively regulate SUMM2‐mediated signaling. Our finding highlights a new defense mechanism where RLKs promote NLR‐mediated immunity.