diff --git a/Marlin/src/pins/esp32/env_validate.h b/Marlin/src/pins/esp32/env_validate.h
index ce14c33414ad..0bfd0ebd92be 100644
--- a/Marlin/src/pins/esp32/env_validate.h
+++ b/Marlin/src/pins/esp32/env_validate.h
@@ -19,8 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(ARDUINO_ARCH_ESP32)
   #error "Oops! Select an ESP32 board in 'Tools > Board.'"
 #endif
+
+#endif
diff --git a/Marlin/src/pins/gd32f1/env_validate.h b/Marlin/src/pins/gd32f1/env_validate.h
index 4b07cce4e5c4..f6882e70d633 100644
--- a/Marlin/src/pins/gd32f1/env_validate.h
+++ b/Marlin/src/pins/gd32f1/env_validate.h
@@ -19,14 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(__STM32F1__, STM32F1)
-  #if DISABLED(ALLOW_STM32F4)
-    #error "Oops! Select an STM32F1 board in 'Tools > Board.'"
-  #elif NOT_TARGET(STM32F4)
-    #error "Oops! Select an STM32F4 board in 'Tools > Board.'"
-  #endif
+  #error "Oops! Select an STM32F1 board in 'Tools > Board.'"
 #endif
 
-#undef ALLOW_STM32F4
+#endif
diff --git a/Marlin/src/pins/lpc1768/env_validate.h b/Marlin/src/pins/lpc1768/env_validate.h
index adb3ea938dc2..8a6a1cebd368 100644
--- a/Marlin/src/pins/lpc1768/env_validate.h
+++ b/Marlin/src/pins/lpc1768/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if ENABLED(REQUIRE_LPC1769) && NOT_TARGET(MCU_LPC1769)
   #error "Oops! Make sure you have the LPC1769 environment selected in your IDE."
@@ -28,3 +29,5 @@
 #endif
 
 #undef REQUIRE_LPC1769
+
+#endif
diff --git a/Marlin/src/pins/lpc1769/env_validate.h b/Marlin/src/pins/lpc1769/env_validate.h
index 2e2b63d5203f..0f62412453a4 100644
--- a/Marlin/src/pins/lpc1769/env_validate.h
+++ b/Marlin/src/pins/lpc1769/env_validate.h
@@ -19,8 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(MCU_LPC1769)
   #error "Oops! Make sure you have the LPC1769 environment selected in your IDE."
 #endif
+
+#endif
diff --git a/Marlin/src/pins/mega/env_validate.h b/Marlin/src/pins/mega/env_validate.h
index 97c52d4e5e05..7b6462ab7a97 100644
--- a/Marlin/src/pins/mega/env_validate.h
+++ b/Marlin/src/pins/mega/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(__AVR_ATmega2560__)
   #if DISABLED(ALLOW_MEGA1280)
@@ -30,3 +31,5 @@
 #endif
 
 #undef ALLOW_MEGA1280
+
+#endif
diff --git a/Marlin/src/pins/rambo/env_validate.h b/Marlin/src/pins/rambo/env_validate.h
index 84cf8392cdfc..ce2818f596d3 100644
--- a/Marlin/src/pins/rambo/env_validate.h
+++ b/Marlin/src/pins/rambo/env_validate.h
@@ -19,8 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(__AVR_ATmega2560__)
   #error "Oops! Select 'Arduino Mega 2560 or Rambo' in 'Tools > Board.'"
 #endif
+
+#endif
diff --git a/Marlin/src/pins/ramps/env_validate.h b/Marlin/src/pins/ramps/env_validate.h
index 6006a78f013c..86d7bce16c16 100644
--- a/Marlin/src/pins/ramps/env_validate.h
+++ b/Marlin/src/pins/ramps/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if ENABLED(ALLOW_SAM3X8E)
   #if NOT_TARGET(__SAM3X8E__, __AVR_ATmega2560__)
@@ -33,3 +34,5 @@
 
 #undef ALLOW_SAM3X8E
 #undef REQUIRE_MEGA2560
+
+#endif
diff --git a/Marlin/src/pins/sam/env_validate.h b/Marlin/src/pins/sam/env_validate.h
index 09bcd1364921..c6f4d76894be 100644
--- a/Marlin/src/pins/sam/env_validate.h
+++ b/Marlin/src/pins/sam/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if BOTH(ALLOW_MEGA1280, ALLOW_MEGA2560) && NOT_TARGET(__SAM3X8E__, __AVR_ATmega1280__, __AVR_ATmega2560__)
   #error "Oops! Select 'Arduino Due or Mega' in 'Tools > Board.'"
@@ -31,3 +32,5 @@
 
 #undef ALLOW_MEGA1280
 #undef ALLOW_MEGA2560
+
+#endif
diff --git a/Marlin/src/pins/sanguino/env_validate.h b/Marlin/src/pins/sanguino/env_validate.h
index d229b6f102e4..bd7947f469a5 100644
--- a/Marlin/src/pins/sanguino/env_validate.h
+++ b/Marlin/src/pins/sanguino/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if ENABLED(ALLOW_MEGA644)
   #if NOT_TARGET(__AVR_ATmega644__, __AVR_ATmega644P__, __AVR_ATmega1284P__)
@@ -40,3 +41,5 @@
 #undef ALLOW_MEGA644
 #undef ALLOW_MEGA644P
 #undef REQUIRE_MEGA644P
+
+#endif
diff --git a/Marlin/src/pins/stm32f1/env_validate.h b/Marlin/src/pins/stm32f1/env_validate.h
index 2d325428ac8c..47399a062d6c 100644
--- a/Marlin/src/pins/stm32f1/env_validate.h
+++ b/Marlin/src/pins/stm32f1/env_validate.h
@@ -19,7 +19,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(__STM32F1__, STM32F1)
   #if DISABLED(ALLOW_STM32F4)
@@ -30,3 +31,5 @@
 #endif
 
 #undef ALLOW_STM32F4
+
+#endif
diff --git a/Marlin/src/pins/stm32f4/env_validate.h b/Marlin/src/pins/stm32f4/env_validate.h
index c01401f06c9a..91adbfc86929 100644
--- a/Marlin/src/pins/stm32f4/env_validate.h
+++ b/Marlin/src/pins/stm32f4/env_validate.h
@@ -19,10 +19,13 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(STM32F4) && (DISABLED(ALLOW_STM32DUINO) || NOT_TARGET(STM32F4xx))
   #error "Oops! Select an STM32F4 board in 'Tools > Board.'"
 #endif
 
 #undef ALLOW_STM32DUINO
+
+#endif
diff --git a/Marlin/src/pins/stm32g0/env_validate.h b/Marlin/src/pins/stm32g0/env_validate.h
index a7be76bd8bb1..03887eb7a491 100644
--- a/Marlin/src/pins/stm32g0/env_validate.h
+++ b/Marlin/src/pins/stm32g0/env_validate.h
@@ -19,8 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(STM32G0xx) || NOT_TARGET(STM32G0B1xx)
   #error "Oops! Select an STM32G0 board in 'Tools > Board.'"
 #endif
+
+#endif
diff --git a/Marlin/src/pins/stm32h7/env_validate.h b/Marlin/src/pins/stm32h7/env_validate.h
index 0c515e5df6be..7feaf2095909 100644
--- a/Marlin/src/pins/stm32h7/env_validate.h
+++ b/Marlin/src/pins/stm32h7/env_validate.h
@@ -19,8 +19,11 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(STM32H7)
   #error "Oops! Select an STM32H7 board in 'Tools > Board.'"
 #endif
+
+#endif
diff --git a/Marlin/src/pins/teensy2/env_validate.h b/Marlin/src/pins/teensy2/env_validate.h
index 5f0ea4f3b672..8fd6fba31932 100644
--- a/Marlin/src/pins/teensy2/env_validate.h
+++ b/Marlin/src/pins/teensy2/env_validate.h
@@ -19,10 +19,13 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
-#pragma once
+#ifndef ENV_VALIDATE_H
+#define ENV_VALIDATE_H
 
 #if NOT_TARGET(__AVR_AT90USB1286__) && (DISABLED(ALLOW_AT90USB1286P) || NOT_TARGET(__AVR_AT90USB1286P__))
   #error "Oops! Select 'Teensy++ 2.0' or 'Printrboard' in 'Tools > Board.'"
 #endif
 
 #undef ALLOW_AT90USB1286P
+
+#endif