diff --git a/SConscript.boardloader b/SConscript.boardloader
index 31c85e6bd6..c09567d49d 100644
--- a/SConscript.boardloader
+++ b/SConscript.boardloader
@@ -104,9 +104,9 @@ env.Replace(
     '-nostdlib '
     '-std=gnu99 -Wall -Werror -Wdouble-promotion -Wpointer-arith '
     '-mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard '
-    '-fsingle-precision-constant -fdata-sections -ffunction-sections ' +
-    '-fstack-protector-all ' +
-    CCFLAGS_MOD,
+    '-fsingle-precision-constant -fdata-sections -ffunction-sections '
+    '-fstack-protector-all '
+    + CCFLAGS_MOD,
     CCFLAGS_QSTR='-DNO_QSTR -DN_X64 -DN_X86 -DN_THUMB',
     LINKFLAGS='-nostdlib -T embed/boardloader/memory.ld --gc-sections',
     CPPPATH=[
diff --git a/SConscript.bootloader b/SConscript.bootloader
index 244afb3e92..2a7fdb566e 100644
--- a/SConscript.bootloader
+++ b/SConscript.bootloader
@@ -121,9 +121,9 @@ env.Replace(
     '-nostdlib '
     '-std=gnu99 -Wall -Werror -Wdouble-promotion -Wpointer-arith '
     '-mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard '
-    '-fsingle-precision-constant -fdata-sections -ffunction-sections ' +
-    '-fstack-protector-all ' +
-    CCFLAGS_MOD,
+    '-fsingle-precision-constant -fdata-sections -ffunction-sections '
+    '-fstack-protector-all '
+    + CCFLAGS_MOD,
     CCFLAGS_QSTR='-DNO_QSTR -DN_X64 -DN_X86 -DN_THUMB',
     LINKFLAGS='-nostdlib -T embed/bootloader/memory.ld --gc-sections',
     CPPPATH=[
diff --git a/SConscript.firmware b/SConscript.firmware
index 2a37c74a8d..b9b5a3a542 100644
--- a/SConscript.firmware
+++ b/SConscript.firmware
@@ -322,8 +322,8 @@ env.Replace(
     '-nostdlib '
     '-std=gnu99 -Wall -Werror -Wdouble-promotion -Wpointer-arith '
     '-mthumb -mtune=cortex-m4 -mcpu=cortex-m4 -mfpu=fpv4-sp-d16 -mfloat-abi=hard '
-    '-fsingle-precision-constant -fdata-sections -ffunction-sections ' +
-    CCFLAGS_MOD,
+    '-fsingle-precision-constant -fdata-sections -ffunction-sections '
+    + CCFLAGS_MOD,
     CCFLAGS_QSTR='-DNO_QSTR -DN_X64 -DN_X86 -DN_THUMB',
     CCFLAGS_OPT='-O3',
     LINKFLAGS='-nostdlib -T embed/firmware/memory.ld --gc-sections',