Influenza virus RNA promoter panhandle structures are believed to be sensed by RIG-I. The occurrence of mismatches in this dsRNA structure raises questions about their effect on innate sensing. Our results suggest that mismatches in vRNA promoters decrease binding to RIG-I in vivo, affecting RNA/RIG-I complex formation, and preventing RIG-I activation. These results can be inferred to apply to other viruses and suggest that mismatches may represent a general viral strategy to escape RIG-I sensing.