diff --git a/examples/RadiativeTransferTests/RandomizedBox_3D/randomized-rt.yml b/examples/RadiativeTransferTests/RandomizedBox_3D/randomized-rt.yml
index 340aac434b3d9fe08fc45c577abd379e41b87bef..2027cd976588b9dc8d2ed3c9f7b46a7422eafce1 100644
--- a/examples/RadiativeTransferTests/RandomizedBox_3D/randomized-rt.yml
+++ b/examples/RadiativeTransferTests/RandomizedBox_3D/randomized-rt.yml
@@ -33,6 +33,7 @@ SPH:
   resolution_eta:        1.2348   # Target smoothing length in units of the mean inter-particle separation (1.2348 == 48Ngbs with the cubic spline kernel).
   CFL_condition:         0.6      # Courant-Friedrich-Levy condition for time integration.
   minimal_temperature:   10.      # Kelvin
+  h_max:                 45.
 
 # Parameters related to the initial conditions
 InitialConditions:
diff --git a/src/rt/GEAR/rt_iact.h b/src/rt/GEAR/rt_iact.h
index 9fce2eeb39b4b10f6985cb8ff306f08064e807d0..b356dd4d3ba5fc8a90a5a78964ec6a72f3394416 100644
--- a/src/rt/GEAR/rt_iact.h
+++ b/src/rt/GEAR/rt_iact.h
@@ -97,7 +97,7 @@ runner_iact_nonsym_rt_injection_prep(const float r2, const float dx[3],
  * @param rt_props Properties of the RT scheme.
  */
 __attribute__((always_inline)) INLINE static void runner_iact_rt_inject(
-    const float r2, float dx[3], const float hi, const float hj,
+    const float r2, const float dx[3], const float hi, const float hj,
     struct spart *restrict si, struct part *restrict pj, const float a,
     const float H, const struct rt_props *rt_props) {
 
diff --git a/src/rt/SPHM1RT/rt_iact.h b/src/rt/SPHM1RT/rt_iact.h
index bead428d752b2cd83c4e462b48c2910ad23abc20..5b8ddd84999351111faebddde9d00d04a95d24e0 100644
--- a/src/rt/SPHM1RT/rt_iact.h
+++ b/src/rt/SPHM1RT/rt_iact.h
@@ -100,7 +100,7 @@ runner_iact_nonsym_rt_injection_prep(const float r2, const float dx[3],
  * @param rt_props Properties of the RT scheme.
  */
 __attribute__((always_inline)) INLINE static void runner_iact_rt_inject(
-    const float r2, float dx[3], const float hi, const float hj,
+    const float r2, const float dx[3], const float hi, const float hj,
     struct spart *restrict si, struct part *restrict pj, const float a,
     const float H, const struct rt_props *rt_props) {
 
diff --git a/src/rt/debug/rt_iact.h b/src/rt/debug/rt_iact.h
index d4a4f0d08c8fe004259035c25dbe7138a30ede54..29538711ef033baa8eae5e3f75fe2302a7df5549 100644
--- a/src/rt/debug/rt_iact.h
+++ b/src/rt/debug/rt_iact.h
@@ -66,7 +66,7 @@ runner_iact_nonsym_rt_injection_prep(const float r2, const float dx[3],
  * @param rt_props Properties of the RT scheme.
  */
 __attribute__((always_inline)) INLINE static void runner_iact_rt_inject(
-    const float r2, float dx[3], const float hi, const float hj,
+    const float r2, const float dx[3], const float hi, const float hj,
     struct spart *restrict si, struct part *restrict pj, const float a,
     const float H, const struct rt_props *rt_props) {