diff --git a/inst/stan/glm_multi_beta_binomial.stan b/inst/stan/glm_multi_beta_binomial.stan
index 086691fe..79c6bc65 100644
--- a/inst/stan/glm_multi_beta_binomial.stan
+++ b/inst/stan/glm_multi_beta_binomial.stan
@@ -277,7 +277,7 @@ model{
   }
 
   // // Priors abundance
-  beta_raw_raw[1] ~ normal ( 0, x_raw_sigma );
+  beta_raw_raw[1] ~ normal ( 0, 3 );
   if(C>1) for(c in 2:C) to_vector(beta_raw_raw[c]) ~ normal ( 0, x_raw_sigma );
 
   // Hyper priors