diff --git a/include/mujoco/mujoco.h b/include/mujoco/mujoco.h
index 6c03bf98..fc04d8eb 100644
--- a/include/mujoco/mujoco.h
+++ b/include/mujoco/mujoco.h
@@ -1087,7 +1087,7 @@ MJAPI const char* mju_type2Str(int type);
 MJAPI int mju_str2Type(const char* str);
 
 // Construct a warning message given the warning type and info.
-MJAPI const char* mju_warningText(int warning, int info);
+MJAPI const char* mju_warningText(int warning, size_t info);
 
 // Return 1 if nan or abs(x)>mjMAXVAL, 0 otherwise. Used by check functions.
 MJAPI int mju_isBad(mjtNum x);
diff --git a/introspect/functions.py b/introspect/functions.py
index 65d92a61..f21d82e5 100644
--- a/introspect/functions.py
+++ b/introspect/functions.py
@@ -6886,7 +6886,7 @@ FUNCTIONS: Mapping[str, FunctionDecl] = dict([
              ),
              FunctionParameterDecl(
                  name='info',
-                 type=ValueType(name='int'),
+                 type=ValueType(name='size_t'),
              ),
          ),
          doc='Construct a warning message given the warning type and info.',
diff --git a/src/engine/engine_util_misc.c b/src/engine/engine_util_misc.c
index df7c71ec..06f44680 100644
--- a/src/engine/engine_util_misc.c
+++ b/src/engine/engine_util_misc.c
@@ -947,45 +947,45 @@ int mju_str2Type(const char* str) {
 
 
 // warning text
-const char* mju_warningText(int warning, int info) {
+const char* mju_warningText(int warning, size_t info) {
   static char str[1000];
 
   switch (warning) {
   case mjWARN_INERTIA:
-    mjSNPRINTF(str, "Inertia matrix is too close to singular at DOF %d. Check model.", info);
+    mjSNPRINTF(str, "Inertia matrix is too close to singular at DOF %zu. Check model.", info);
     break;
 
   case mjWARN_CONTACTFULL:
     mjSNPRINTF(str,
                "Too many contacts. Either the arena memory is full, or nconmax is specified and is "
                "exceeded. Increase arena memory allocation, or increase/remove nconmax. "
-               "(ncon = %d)", info);
+               "(ncon = %zu)", info);
     break;
 
   case mjWARN_CNSTRFULL:
     mjSNPRINTF(str,
                "Insufficient arena memory for the number of constraints generated. "
-               "Increase arena memory allocation above %d bytes.", info);
+               "Increase arena memory allocation above %zu bytes.", info);
     break;
 
   case mjWARN_VGEOMFULL:
-    mjSNPRINTF(str, "Pre-allocated visual geom buffer is full. Increase maxgeom above %d.", info);
+    mjSNPRINTF(str, "Pre-allocated visual geom buffer is full. Increase maxgeom above %zu.", info);
     break;
 
   case mjWARN_BADQPOS:
-    mjSNPRINTF(str, "Nan, Inf or huge value in QPOS at DOF %d. The simulation is unstable.", info);
+    mjSNPRINTF(str, "Nan, Inf or huge value in QPOS at DOF %zu. The simulation is unstable.", info);
     break;
 
   case mjWARN_BADQVEL:
-    mjSNPRINTF(str, "Nan, Inf or huge value in QVEL at DOF %d. The simulation is unstable.", info);
+    mjSNPRINTF(str, "Nan, Inf or huge value in QVEL at DOF %zu. The simulation is unstable.", info);
     break;
 
   case mjWARN_BADQACC:
-    mjSNPRINTF(str, "Nan, Inf or huge value in QACC at DOF %d. The simulation is unstable.", info);
+    mjSNPRINTF(str, "Nan, Inf or huge value in QACC at DOF %zu. The simulation is unstable.", info);
     break;
 
   case mjWARN_BADCTRL:
-    mjSNPRINTF(str, "Nan, Inf or huge value in CTRL at ACTUATOR %d. The simulation is unstable.",
+    mjSNPRINTF(str, "Nan, Inf or huge value in CTRL at ACTUATOR %zu. The simulation is unstable.",
                info);
     break;
 
diff --git a/src/engine/engine_util_misc.h b/src/engine/engine_util_misc.h
index 93f6224c..8a2b58a6 100644
--- a/src/engine/engine_util_misc.h
+++ b/src/engine/engine_util_misc.h
@@ -22,6 +22,8 @@
 extern "C" {
 #endif
 
+#include <stddef.h>
+
 //------------------------------ tendons and actuators ---------------------------------------------
 
 // wrap tendons around spheres and cylinders
@@ -86,7 +88,7 @@ MJAPI const char* mju_type2Str(int type);
 MJAPI int mju_str2Type(const char* str);
 
 // warning text
-MJAPI const char* mju_warningText(int warning, int info);
+MJAPI const char* mju_warningText(int warning, size_t info);
 
 // return 1 if nan or abs(x)>mjMAXVAL, 0 otherwise
 MJAPI int mju_isBad(mjtNum x);
diff --git a/unity/Runtime/Bindings/MujocoBindings.cs b/unity/Runtime/Bindings/MujocoBindings.cs
index d581ea32..9c19b403 100644
--- a/unity/Runtime/Bindings/MujocoBindings.cs
+++ b/unity/Runtime/Bindings/MujocoBindings.cs
@@ -3502,7 +3502,7 @@ public static unsafe extern int mju_str2Type([MarshalAs(UnmanagedType.LPStr)]str
 
 [DllImport("mujoco", CallingConvention = CallingConvention.Cdecl)]
 [return: MarshalAs(UnmanagedType.LPStr)]
-public static unsafe extern string mju_warningText(int warning, int info);
+public static unsafe extern string mju_warningText(int warning, UIntPtr info);
 
 [DllImport("mujoco", CallingConvention = CallingConvention.Cdecl)]
 public static unsafe extern int mju_isBad(double x);