diff --git a/src/lyapunov.c b/src/lyapunov.c
index ced9ac3..8cf2e56 100644
--- a/src/lyapunov.c
+++ b/src/lyapunov.c
@@ -21,7 +21,7 @@ limitations under the License.
 #include <math.h>
 #include <stdlib.h>
 
-#define MATSIZE (K1*(2*(K2+1)+K2))
+#define MATSIZE (K1*(2*K2+1)+K2)
 
 // compute Lyapunov exponents
 int lyapunov(