diff --git a/libraries/AC_PID/AC_PID.cpp b/libraries/AC_PID/AC_PID.cpp
index 51b216c42d..4e8c1b5812 100644
--- a/libraries/AC_PID/AC_PID.cpp
+++ b/libraries/AC_PID/AC_PID.cpp
@@ -64,6 +64,12 @@ const AP_Param::GroupInfo AC_PID::var_info[] = {
     // @User: Advanced
     AP_GROUPINFO_FLAGS_DEFAULT_POINTER("SMAX", 12, AC_PID, _slew_rate_max, default_slew_rate_max),
 
+    // @Param: PDMX
+    // @DisplayName: PD sum maximum
+    // @Description: The maximum/minimum value that the sum of the P and D term can output
+    // @User: Advanced
+    AP_GROUPINFO("PDMX", 13, AC_PID, _kpdmax, 0),
+
     AP_GROUPEND
 };
 
@@ -172,7 +178,10 @@ float AC_PID::update_all(float target, float measurement, float dt, bool limit,
     _pid_info.P = P_out;
     _pid_info.D = D_out;
 
-    return P_out + _integrator + D_out;
+    if (is_positive(_kpdmax)) {
+        return constrain_float(P_out + D_out, -_kpdmax, _kpdmax) + _integrator;
+    }
+    return P_out + D_out + _integrator;
 }
 
 //  update_error - set error input to PID controller and calculate outputs
@@ -225,7 +234,10 @@ float AC_PID::update_error(float error, float dt, bool limit)
     _pid_info.P = P_out;
     _pid_info.D = D_out;
 
-    return P_out + _integrator + D_out;
+    if (is_positive(_kpdmax)) {
+        return constrain_float(P_out + D_out, -_kpdmax, _kpdmax) + _integrator;
+    }
+    return P_out + D_out + _integrator;
 }
 
 //  update_i - update the integral
@@ -279,6 +291,8 @@ void AC_PID::load_gains()
     _kff.load();
     _kimax.load();
     _kimax.set(fabsf(_kimax));
+    _kpdmax.load();
+    _kpdmax.set(fabsf(_kpdmax));
     _filt_T_hz.load();
     _filt_E_hz.load();
     _filt_D_hz.load();
diff --git a/libraries/AC_PID/AC_PID.h b/libraries/AC_PID/AC_PID.h
index 5f3befd096..7ae4592473 100644
--- a/libraries/AC_PID/AC_PID.h
+++ b/libraries/AC_PID/AC_PID.h
@@ -103,6 +103,7 @@ public:
     AP_Float &kI() { return _ki; }
     AP_Float &kD() { return _kd; }
     AP_Float &kIMAX() { return _kimax; }
+    AP_Float &kPDMAX() { return _kpdmax; }
     AP_Float &ff() { return _kff;}
     AP_Float &filt_T_hz() { return _filt_T_hz; }
     AP_Float &filt_E_hz() { return _filt_E_hz; }
@@ -110,6 +111,7 @@ public:
     AP_Float &slew_limit() { return _slew_rate_max; }
 
     float imax() const { return _kimax.get(); }
+    float pdmax() const { return _kpdmax.get(); }
     float get_filt_T_alpha(float dt) const;
     float get_filt_E_alpha(float dt) const;
     float get_filt_D_alpha(float dt) const;
@@ -120,6 +122,7 @@ public:
     void kD(const float v) { _kd.set(v); }
     void ff(const float v) { _kff.set(v); }
     void imax(const float v) { _kimax.set(fabsf(v)); }
+    void pdmax(const float v) { _kpdmax.set(fabsf(v)); }
     void filt_T_hz(const float v);
     void filt_E_hz(const float v);
     void filt_D_hz(const float v);
@@ -160,6 +163,7 @@ protected:
     AP_Float _kd;
     AP_Float _kff;
     AP_Float _kimax;
+    AP_Float _kpdmax;
     AP_Float _filt_T_hz;         // PID target filter frequency in Hz
     AP_Float _filt_E_hz;         // PID error filter frequency in Hz
     AP_Float _filt_D_hz;         // PID derivative filter frequency in Hz