diff --git a/tests/BasicSimulator.cpp b/tests/BasicSimulator.cpp
index 220274a3..f99bf8e8 100644
--- a/tests/BasicSimulator.cpp
+++ b/tests/BasicSimulator.cpp
@@ -486,8 +486,8 @@ int main(int argc, char **argv)
 		FlipID(id,Nx*Ny*Nz);
 	}
 #else
-	// If negative phi_s is chosen, flip the ID for the wetting and non-wetting phase
-	if (phi_s < 0.0 && !pBC){
+	// If positive phi_s is chosen, flip the ID for the wetting and non-wetting phase
+	if (phi_s > 0.0 && !pBC){
 		phi_s = -phi_s;
 	 	das = (phi_s+1.0)*0.5;
 		dbs = 1.0 - das;
diff --git a/tests/lb2_Color_wia_mpi.cpp b/tests/lb2_Color_wia_mpi.cpp
index a6ba7b24..473dbc08 100644
--- a/tests/lb2_Color_wia_mpi.cpp
+++ b/tests/lb2_Color_wia_mpi.cpp
@@ -507,8 +507,8 @@ int main(int argc, char **argv)
 		FlipID(id,Nx*Ny*Nz);
 	}
 #else
-	// If negative phi_s is chosen, flip the ID for the wetting and non-wetting phase
-	if (phi_s < 0.0 && !pBC){
+	// If positive phi_s is chosen, flip the ID for the wetting and non-wetting phase
+	if (phi_s > 0.0 && !pBC){
 		phi_s = -phi_s;
 	 	das = (phi_s+1.0)*0.5;
 		dbs = 1.0 - das;