diff --git a/Marlin/M100_Free_Mem_Chk.cpp b/Marlin/M100_Free_Mem_Chk.cpp
index 6620b0a16..d7f38aa2d 100644
--- a/Marlin/M100_Free_Mem_Chk.cpp
+++ b/Marlin/M100_Free_Mem_Chk.cpp
@@ -45,13 +45,18 @@
  *
  * Initial version by Roxy-3D
  */
-#define M100_FREE_MEMORY_DUMPER     // Enable for the `M110 D` Dump sub-command
-#define M100_FREE_MEMORY_CORRUPTOR  // Enable for the `M100 C` Corrupt sub-command
 
 #include "MarlinConfig.h"
 
 #if ENABLED(M100_FREE_MEMORY_WATCHER)
 
+#define M100_FREE_MEMORY_DUMPER     // Enable for the `M110 D` Dump sub-command
+#define M100_FREE_MEMORY_CORRUPTOR  // Enable for the `M100 C` Corrupt sub-command
+
+#include "Marlin.h"
+#include "gcode.h"
+#include "hex_print_routines.h"
+
 #define TEST_BYTE ((char) 0xE5)
 
 extern char command_queue[BUFSIZE][MAX_CMD_SIZE];
@@ -60,10 +65,6 @@ extern char* __brkval;
 extern size_t  __heap_start, __heap_end, __flp;
 extern char __bss_end;
 
-#include "Marlin.h"
-#include "gcode.h"
-#include "hex_print_routines.h"
-
 //
 // Utility functions
 //
diff --git a/Marlin/Marlin.h b/Marlin/Marlin.h
index 308b9f850..92b06fd3f 100644
--- a/Marlin/Marlin.h
+++ b/Marlin/Marlin.h
@@ -417,6 +417,7 @@ void report_current_position();
 
 #if HAS_BED_PROBE
   extern float zprobe_zoffset;
+  bool set_probe_deployed(const bool deploy);
   #define DEPLOY_PROBE() set_probe_deployed(true)
   #define STOW_PROBE() set_probe_deployed(false)
 #else
diff --git a/Marlin/Marlin_main.cpp b/Marlin/Marlin_main.cpp
index d23ec1488..61a7534c7 100644
--- a/Marlin/Marlin_main.cpp
+++ b/Marlin/Marlin_main.cpp
@@ -350,8 +350,6 @@
 
 #if ENABLED(AUTO_BED_LEVELING_UBL)
   #include "ubl.h"
-  extern bool defer_return_to_status;
-  unified_bed_leveling ubl;
 #endif
 
 #if ENABLED(CNC_COORDINATE_SYSTEMS)
@@ -2069,7 +2067,7 @@ static void clean_up_after_endstop_or_probe_move() {
   #endif // BLTOUCH
 
   // returns false for ok and true for failure
-  bool set_probe_deployed(bool deploy) {
+  bool set_probe_deployed(const bool deploy) {
 
     #if ENABLED(DEBUG_LEVELING_FEATURE)
       if (DEBUGGING(LEVELING)) {
diff --git a/Marlin/dac_mcp4728.cpp b/Marlin/dac_mcp4728.cpp
index a06346c6e..783f9fb5e 100644
--- a/Marlin/dac_mcp4728.cpp
+++ b/Marlin/dac_mcp4728.cpp
@@ -30,11 +30,13 @@
  * http://arduino.cc/forum/index.php/topic,51842.0.html
  */
 
-#include "dac_mcp4728.h"
-#include "enum.h"
+#include "MarlinConfig.h"
 
 #if ENABLED(DAC_STEPPER_CURRENT)
 
+#include "dac_mcp4728.h"
+#include "enum.h"
+
 uint16_t mcp4728_values[XYZE];
 
 /**
diff --git a/Marlin/hex_print_routines.cpp b/Marlin/hex_print_routines.cpp
index 65b97fc18..38f2ff7b2 100644
--- a/Marlin/hex_print_routines.cpp
+++ b/Marlin/hex_print_routines.cpp
@@ -19,11 +19,13 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *
  */
-#include "Marlin.h"
-#include "gcode.h"
+
+#include "MarlinConfig.h"
 
 #if ENABLED(AUTO_BED_LEVELING_UBL) || ENABLED(M100_FREE_MEMORY_WATCHER) || ENABLED(DEBUG_GCODE_PARSER)
 
+#include "Marlin.h"
+#include "gcode.h"
 #include "hex_print_routines.h"
 
 static char _hex[7] = "0x0000";
diff --git a/Marlin/planner_bezier.cpp b/Marlin/planner_bezier.cpp
index d07863d13..4686c571e 100644
--- a/Marlin/planner_bezier.cpp
+++ b/Marlin/planner_bezier.cpp
@@ -27,13 +27,14 @@
  *
  */
 
-#include "Marlin.h"
+#include "MarlinConfig.h"
 
 #if ENABLED(BEZIER_CURVE_SUPPORT)
 
 #include "planner.h"
 #include "language.h"
 #include "temperature.h"
+#include "Marlin.h"
 
 // See the meaning in the documentation of cubic_b_spline().
 #define MIN_STEP 0.002
diff --git a/Marlin/printcounter.cpp b/Marlin/printcounter.cpp
index 794a1995e..1b046edcb 100644
--- a/Marlin/printcounter.cpp
+++ b/Marlin/printcounter.cpp
@@ -20,6 +20,10 @@
  *
  */
 
+#include "MarlinConfig.h"
+
+#if ENABLED(PRINTCOUNTER)
+
 #include "Marlin.h"
 #include "printcounter.h"
 #include "duration_t.h"
@@ -232,3 +236,5 @@ void PrintCounter::reset() {
   }
 
 #endif
+
+#endif // PRINTCOUNTER
diff --git a/Marlin/twibus.cpp b/Marlin/twibus.cpp
index 4e29ef883..777d151e4 100644
--- a/Marlin/twibus.cpp
+++ b/Marlin/twibus.cpp
@@ -20,12 +20,13 @@
  *
  */
 
-#include "Marlin.h"
+#include "MarlinConfig.h"
 
 #if ENABLED(EXPERIMENTAL_I2CBUS)
 
 #include "twibus.h"
 #include <Wire.h>
+#include "Marlin.h"
 
 TWIBus::TWIBus() {
   #if I2C_SLAVE_ADDRESS == 0
diff --git a/Marlin/ubl.cpp b/Marlin/ubl.cpp
index 11a2a2223..819f5ecad 100644
--- a/Marlin/ubl.cpp
+++ b/Marlin/ubl.cpp
@@ -20,15 +20,18 @@
  *
  */
 
-#include "Marlin.h"
-#include "math.h"
+#include "MarlinConfig.h"
 
 #if ENABLED(AUTO_BED_LEVELING_UBL)
 
+  #include "Marlin.h"
   #include "ubl.h"
   #include "hex_print_routines.h"
   #include "temperature.h"
   #include "planner.h"
+  #include "math.h"
+
+  unified_bed_leveling ubl;
 
   uint8_t ubl_cnt = 0;
 
diff --git a/Marlin/vector_3.cpp b/Marlin/vector_3.cpp
index 8c30830e6..bc62e2116 100644
--- a/Marlin/vector_3.cpp
+++ b/Marlin/vector_3.cpp
@@ -38,11 +38,14 @@
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
-#include <math.h>
-#include "Marlin.h"
+
+#include "MarlinConfig.h"
 
 #if HAS_ABL
+
 #include "vector_3.h"
+#include "serial.h"
+#include <math.h>
 
 vector_3::vector_3() : x(0), y(0), z(0) { }