French Defence vs KIA 5.c3

Hey there, I've been playing the French Defence for quite a while and am now struggling against a specific line in the KIA.

Against someone who plays 5.g3, I can go for an early Bc5 without having to fear b4, and am ready to play e5 in order to block white's light-squared bishop. Later on, I can attack the f2 pawn with moves such as Nb4 and obtain a decent game. Against 5.c3, however, those options are no longer possible. In order to avoid b4, I've seen many players in the database using a5, but this allows White to play e5 and d4, and obtain a French-like position where black can't play c5. What would you recommend me to do against such a setup by white ? Any help is appreciated

Can't really help you.  Speaking as a French player, having faced the KIA numerous times, I always have, and always will, play 4...c5 instead of 4...Nc6.

I used to play this as white and some thoughts...

Indeed, this set up with dxe4-Bc5, if allowed, is quite ok for black. The best way for white is not to play "as usual" with g3, but with a Philidor reversed set up.

I've always played with 5.c3 a5 6.Be2 playing a Philidor reversed with a playable game for both sides.

About 5.c3 a5 6.e5 Black, deprived of c5, can react with f6 and threats to win the battle in centre.

White should answer f6 with Bb5 at some points, to control important central squares, with a completely different kind of position than Philidor's like given above.

Thanks for your helpful input After taking your answers into consideration and looking at some databases, I came up with the following plan:

5.e5 doesn't seem to give white any opening advantage, eventhough the line with 7.Bb5 is quite scary. Against 5.c3, I think that 5...Bd6 is a good answer (avoiding e5). Although it is only the fifth most played move in the position in my database, it seems that Caruana used it multiple times, and it's also Stockfish first recommendation. If white responds with 6.g3, I can still apply the dxe4 ... dxe4 into e5 strategy to obtain a decent game. The two critical moves seem to be 6.Be2 and 6.b4, lines I'm still studying. What would you think about this ?