diff --git a/matlab/nass_1_active_damping.m b/matlab/nass_1_active_damping.m
index 47dd50c..778502d 100644
--- a/matlab/nass_1_active_damping.m
+++ b/matlab/nass_1_active_damping.m
@@ -269,11 +269,11 @@ xlim([freqs(1), freqs(end)]);
 %% Verify that parallel stiffness permits to have a stable plant
 Kiff_pure_int = -200/s*eye(6);
 
-if not(isstable(feedback(G_iff_m25_Rz, Kiff_pure_int, 1)))
+if isstable(feedback(G_iff_m25_Rz_no_kp, Kiff_pure_int, 1))
     disp("Decentralized IFF is not stable with rotation")
 end
 
-if isstable(feedback(G_iff_m25_Rz_no_kp, Kiff_pure_int, 1))
+if not(isstable(feedback(G_iff_m25_Rz, Kiff_pure_int, 1)))
     disp("Parallel stiffness makes the decentralized IFF stable")
 else
     warning("Decentralized IFF is not stable even with the parallel stiffness")
diff --git a/simscape-nass.org b/simscape-nass.org
index 1a9365f..8ac8f46 100644
--- a/simscape-nass.org
+++ b/simscape-nass.org
@@ -1177,11 +1177,11 @@ The overall gain was then increased to obtain a large loop gain around the reson
 %% Verify that parallel stiffness permits to have a stable plant
 Kiff_pure_int = -200/s*eye(6);
 
-if not(isstable(feedback(G_iff_m25_Rz, Kiff_pure_int, 1)))
+if isstable(feedback(G_iff_m25_Rz_no_kp, Kiff_pure_int, 1))
     disp("Decentralized IFF is not stable with rotation")
 end
 
-if isstable(feedback(G_iff_m25_Rz_no_kp, Kiff_pure_int, 1))
+if not(isstable(feedback(G_iff_m25_Rz, Kiff_pure_int, 1)))
     disp("Parallel stiffness makes the decentralized IFF stable")
 else
     warning("Decentralized IFF is not stable even with the parallel stiffness")