diff --git a/Regression/Checksum/benchmarks_json/test_1d_theta_implicit_planar_pinch.json b/Regression/Checksum/benchmarks_json/test_1d_theta_implicit_planar_pinch.json
index e0181550184..51b96021c09 100644
--- a/Regression/Checksum/benchmarks_json/test_1d_theta_implicit_planar_pinch.json
+++ b/Regression/Checksum/benchmarks_json/test_1d_theta_implicit_planar_pinch.json
@@ -1,29 +1,29 @@
 {
   "lev=0": {
-    "Bx": 2.1912736317756045,
-    "By": 2.4851292469084845,
+    "Bx": 2.347554229130745,
+    "By": 2.254227700454954,
     "Bz": 0.0,
-    "Ex": 502596276.2641554,
-    "Ey": 445077555.93355495,
-    "Ez": 735298254.8259611,
-    "divE": 7738179438748.199,
-    "jx": 20295346360.21621,
-    "jy": 18500166578.05146,
-    "jz": 12896152163.81817,
-    "rho": 68.51529412833617
+    "Ex": 551393126.2574284,
+    "Ey": 491617943.23209137,
+    "Ez": 714658615.6303692,
+    "divE": 7016314161711.369,
+    "jx": 18692954464.699497,
+    "jy": 20177259050.167336,
+    "jz": 12721426909.097504,
+    "rho": 62.123763388017494
   },
-  "electrons": {
-    "particle_momentum_x": 6.633861262255149e-21,
-    "particle_momentum_y": 6.57156805052218e-21,
-    "particle_momentum_z": 6.612071131081156e-21,
-    "particle_position_x": 163.63366259142643,
+  "deuterium": {
+    "particle_momentum_x": 4.035760123452947e-19,
+    "particle_momentum_y": 4.004963598310352e-19,
+    "particle_momentum_z": 4.0782810816965124e-19,
+    "particle_position_x": 163.6336698244632,
     "particle_weight": 1.4999875e+21
   },
-  "deuterium": {
-    "particle_momentum_x": 4.0555219989281625e-19,
-    "particle_momentum_y": 4.012108093779528e-19,
-    "particle_momentum_z": 4.037274466067505e-19,
-    "particle_position_x": 163.63366984188605,
+  "electrons": {
+    "particle_momentum_x": 6.6030232424328065e-21,
+    "particle_momentum_y": 6.60813358729526e-21,
+    "particle_momentum_z": 6.559430730541378e-21,
+    "particle_position_x": 163.63367200208899,
     "particle_weight": 1.4999875e+21
   }
 }
diff --git a/Regression/Checksum/benchmarks_json/test_2d_theta_implicit_planar_pinch.json b/Regression/Checksum/benchmarks_json/test_2d_theta_implicit_planar_pinch.json
index 98897009b30..9e5c71ebed9 100644
--- a/Regression/Checksum/benchmarks_json/test_2d_theta_implicit_planar_pinch.json
+++ b/Regression/Checksum/benchmarks_json/test_2d_theta_implicit_planar_pinch.json
@@ -1,31 +1,31 @@
 {
   "lev=0": {
-    "Bx": 9.069162586111297,
-    "By": 19.361810144285307,
-    "Bz": 12.107034717007863,
-    "Ex": 4193780781.9712296,
-    "Ey": 3007724460.40948,
-    "Ez": 4187550905.2162943,
-    "divE": 46810632867690.65,
-    "jx": 94112859497.26407,
-    "jy": 118766765057.53568,
-    "jz": 136347119759.39658,
-    "rho": 414.24713064231827
+    "Bx": 9.275768517413653,
+    "By": 19.472307474063484,
+    "Bz": 11.610979590557633,
+    "Ex": 4177113295.3698635,
+    "Ey": 2879051080.583498,
+    "Ez": 4181787135.040885,
+    "divE": 47250533638439.05,
+    "jx": 91271135865.5671,
+    "jy": 115116958556.87042,
+    "jz": 142255859953.87067,
+    "rho": 418.1507147637307
   },
-  "electrons": {
-    "particle_momentum_x": 5.2809601200365096e-20,
-    "particle_momentum_y": 5.295981363178306e-20,
-    "particle_momentum_z": 5.2829658537615036e-20,
-    "particle_position_x": 1309.3090607484742,
-    "particle_position_y": 96.00683559953801,
+  "deuterium": {
+    "particle_momentum_x": 3.2203338208705e-18,
+    "particle_momentum_y": 3.2127841653787054e-18,
+    "particle_momentum_z": 3.2284163892421025e-18,
+    "particle_position_x": 1309.3091292829426,
+    "particle_position_y": 96.00796866051637,
     "particle_weight": 1.6501375e+18
   },
-  "deuterium": {
-    "particle_momentum_x": 3.2166143445626475e-18,
-    "particle_momentum_y": 3.2209130431028616e-18,
-    "particle_momentum_z": 3.226813184396913e-18,
-    "particle_position_x": 1309.3091292978781,
-    "particle_position_y": 96.00796866718042,
+  "electrons": {
+    "particle_momentum_x": 5.297572837196199e-20,
+    "particle_momentum_y": 5.298600055672404e-20,
+    "particle_momentum_z": 5.276908853465337e-20,
+    "particle_position_x": 1309.3090771126394,
+    "particle_position_y": 96.00571854694559,
     "particle_weight": 1.6501375e+18
   }
 }
diff --git a/Source/Evolve/WarpXEvolve.cpp b/Source/Evolve/WarpXEvolve.cpp
index 064f61beb10..e5a151f1580 100644
--- a/Source/Evolve/WarpXEvolve.cpp
+++ b/Source/Evolve/WarpXEvolve.cpp
@@ -192,7 +192,8 @@ WarpX::Evolve (int numsteps)
 
         // Update timestep for electrostatic solver if a constant dt is not provided
         // This first synchronizes the position and velocity before setting the new timestep
-        if (electromagnetic_solver_id == ElectromagneticSolverAlgo::None &&
+        if ((electromagnetic_solver_id == ElectromagneticSolverAlgo::None ||
+            evolve_scheme == EvolveScheme::ThetaImplicitEM) &&
             !m_const_dt.has_value() && m_dt_update_interval.contains(step+1)) {
             if (verbose_step) {
                 amrex::Print() << Utils::TextMsg::Info("updating timestep");
@@ -384,13 +385,13 @@ void WarpX::OneStep (
 
     // implicit solver
     if (m_implicit_solver) {
+        // advance fields and particles by one time step
+        m_implicit_solver->OneStep(a_cur_time, a_dt, a_step);
+
         // perform particle collisions
         ExecutePythonCallback("beforecollisions");
         mypc->doCollisions(a_step, a_cur_time, a_dt);
         ExecutePythonCallback("aftercollisions");
-
-        // advance fields and particles by one time step
-        m_implicit_solver->OneStep(a_cur_time, a_dt, a_step);
     }
     // explicit solver
     else {