diff --git a/stim/math/matrix.h b/stim/math/matrix.h
index 50a3b42..f4cbe42 100644
--- a/stim/math/matrix.h
+++ b/stim/math/matrix.h
@@ -38,14 +38,14 @@ struct matrix
 	}
 
 	//create a symmetric matrix given the rhs values, given in column-major order
-	CUDA_CALLABLE matrix<T, N> setsym(T rhs[(N*N+N)/2]){
+	CUDA_CALLABLE void setsym(T rhs[(N*N+N)/2]){
 		const size_t L = (N*N+N)/2;		//store the number of values
 
 		size_t r, c;
 		r = c = 0;
 		for(size_t i = 0; i < L; i++){ 				//for each value
-			if(r == c) M[c * n + r] = rhs[i];
-			else M[c*n + r] = M[r * N + c] = rhs[i];
+			if(r == c) M[c * N + r] = rhs[i];
+			else M[c*N + r] = M[r * N + c] = rhs[i];
 			r++;
 			if(r == N) r = ++c;
 		}
--
libgit2 0.21.4