diff --git a/os/common/startup/ARMCMx/compilers/GCC/crt0_v6m.S b/os/common/startup/ARMCMx/compilers/GCC/crt0_v6m.S
index b3bed66b3..36b96dfe7 100644
--- a/os/common/startup/ARMCMx/compilers/GCC/crt0_v6m.S
+++ b/os/common/startup/ARMCMx/compilers/GCC/crt0_v6m.S
@@ -50,7 +50,7 @@
  * @note    This is required if the boot process is not reliable for whatever
  *          reason (bad ROMs, bad bootloaders, bad debuggers=.
  */
-#if !defined(CRT0_VTOR_INIT) || defined(__DOXYGEN__)
+#if !defined(CRT0_FORCE_MSP_INIT) || defined(__DOXYGEN__)
 #define CRT0_FORCE_MSP_INIT                 TRUE
 #endif
 
diff --git a/os/common/startup/ARMCMx/compilers/GCC/crt0_v7m.S b/os/common/startup/ARMCMx/compilers/GCC/crt0_v7m.S
index 453a9e64c..7d84a7448 100644
--- a/os/common/startup/ARMCMx/compilers/GCC/crt0_v7m.S
+++ b/os/common/startup/ARMCMx/compilers/GCC/crt0_v7m.S
@@ -57,7 +57,7 @@
  * @note    This is required if the boot process is not reliable for whatever
  *          reason (bad ROMs, bad bootloaders, bad debuggers=.
  */
-#if !defined(CRT0_VTOR_INIT) || defined(__DOXYGEN__)
+#if !defined(CRT0_FORCE_MSP_INIT) || defined(__DOXYGEN__)
 #define CRT0_FORCE_MSP_INIT                 TRUE
 #endif
 
diff --git a/readme.txt b/readme.txt
index 8a9babd63..089ea896a 100644
--- a/readme.txt
+++ b/readme.txt
@@ -124,6 +124,8 @@
 - EX:  Updated LIS302DL to 1.1.0 (backported to 18.2.1).
 - EX:  Updated LPS25H to 1.1.0 (backported to 18.2.1).
 - EX:  Updated LSM303DLHC to 1.1.0 (backported to 18.2.1).
+- OTH: Fixed wrong macro check in GCC Cortex-M startup files (bug #947)
+       (backported to 18.2.2 and 17.6.5).
 - HAL: Fixed binary instead of logic operator in STM32F4 HAL (bug #946)
        (backported to 18.2.2 and 17.6.5).
 - HAL: Fixed Mikroe clicker 2 misaligned board file (bug #945)