diff --git a/ports/esp32/boards/GENERIC/board.json b/ports/esp32/boards/GENERIC/board.json
index d08fcfec15..8e2f224328 100644
--- a/ports/esp32/boards/GENERIC/board.json
+++ b/ports/esp32/boards/GENERIC/board.json
@@ -17,11 +17,11 @@
     "thumbnail": "",
     "url": "https://www.espressif.com/en/products/modules",
     "variants": {
-        "idf3": "Compiled with IDF 3.x",
-        "d2wd": "ESP32 D2WD",
-        "spiram": "Support for SPIRAM / WROVER",
-        "unicore": "ESP32 Unicore",
-        "ota": "Support for OTA"
+        "IDF3": "Compiled with IDF 3.x",
+        "D2WD": "ESP32 D2WD",
+        "SPIRAM": "Support for SPIRAM / WROVER",
+        "UNICORE": "ESP32 Unicore",
+        "OTA": "Support for OTA"
     },
     "vendor": "Espressif"
 }
diff --git a/ports/esp32/boards/GENERIC/mpconfigboard.cmake b/ports/esp32/boards/GENERIC/mpconfigboard.cmake
index 29096c2768..14b47b3e59 100644
--- a/ports/esp32/boards/GENERIC/mpconfigboard.cmake
+++ b/ports/esp32/boards/GENERIC/mpconfigboard.cmake
@@ -3,7 +3,7 @@ set(SDKCONFIG_DEFAULTS
     boards/sdkconfig.ble
 )
 
-if(MICROPY_BOARD_VARIANT STREQUAL "d2wd")
+if(MICROPY_BOARD_VARIANT STREQUAL "D2WD")
     set(SDKCONFIG_DEFAULTS
         ${SDKCONFIG_DEFAULTS}
         boards/GENERIC/sdkconfig.d2wd
@@ -14,7 +14,7 @@ if(MICROPY_BOARD_VARIANT STREQUAL "d2wd")
     )
 endif()
 
-if(MICROPY_BOARD_VARIANT STREQUAL "ota")
+if(MICROPY_BOARD_VARIANT STREQUAL "OTA")
     set(SDKCONFIG_DEFAULTS
         ${SDKCONFIG_DEFAULTS}
         boards/GENERIC/sdkconfig.ota
@@ -25,7 +25,7 @@ if(MICROPY_BOARD_VARIANT STREQUAL "ota")
     )
 endif()
 
-if(MICROPY_BOARD_VARIANT STREQUAL "spiram")
+if(MICROPY_BOARD_VARIANT STREQUAL "SPIRAM")
     set(SDKCONFIG_DEFAULTS
         ${SDKCONFIG_DEFAULTS}
         boards/sdkconfig.spiram
@@ -36,7 +36,7 @@ if(MICROPY_BOARD_VARIANT STREQUAL "spiram")
     )
 endif()
 
-if(MICROPY_BOARD_VARIANT STREQUAL "unicore")
+if(MICROPY_BOARD_VARIANT STREQUAL "UNICORE")
     set(SDKCONFIG_DEFAULTS
         ${SDKCONFIG_DEFAULTS}
         boards/GENERIC/sdkconfig.unicore
diff --git a/ports/esp32/boards/GENERIC_S3/board.json b/ports/esp32/boards/GENERIC_S3/board.json
index be2170c12f..671936c922 100644
--- a/ports/esp32/boards/GENERIC_S3/board.json
+++ b/ports/esp32/boards/GENERIC_S3/board.json
@@ -18,6 +18,6 @@
     "url": "https://www.espressif.com/en/products/modules",
     "vendor": "Espressif",
     "variants": {
-        "spiram-oct": "Support for Octal-SPIRAM"
+        "SPIRAM_OCT": "Support for Octal-SPIRAM"
     }
 }
diff --git a/ports/esp32/boards/GENERIC_S3/mpconfigboard.cmake b/ports/esp32/boards/GENERIC_S3/mpconfigboard.cmake
index bd163f9f33..29974aaba4 100644
--- a/ports/esp32/boards/GENERIC_S3/mpconfigboard.cmake
+++ b/ports/esp32/boards/GENERIC_S3/mpconfigboard.cmake
@@ -8,7 +8,7 @@ set(SDKCONFIG_DEFAULTS
     boards/GENERIC_S3/sdkconfig.board
 )
 
-if(MICROPY_BOARD_VARIANT STREQUAL "spiram-oct")
+if(MICROPY_BOARD_VARIANT STREQUAL "SPIRAM_OCT")
     set(SDKCONFIG_DEFAULTS
         ${SDKCONFIG_DEFAULTS}
         boards/sdkconfig.240mhz
diff --git a/ports/esp32/boards/UM_TINYPICO/board.json b/ports/esp32/boards/UM_TINYPICO/board.json
index f6ba9ddb0e..3e15e99112 100644
--- a/ports/esp32/boards/UM_TINYPICO/board.json
+++ b/ports/esp32/boards/UM_TINYPICO/board.json
@@ -24,7 +24,7 @@
     "thumbnail": "",
     "url": "https://www.tinypico.com/",
     "variants": {
-        "idf3": "Compiled with IDF 3.x"
+        "IDF3": "Compiled with IDF 3.x"
     },
     "vendor": "Unexpected Maker"
 }
diff --git a/tools/autobuild/build-boards.sh b/tools/autobuild/build-boards.sh
index f75ccba398..82d7f36057 100755
--- a/tools/autobuild/build-boards.sh
+++ b/tools/autobuild/build-boards.sh
@@ -55,10 +55,10 @@ function build_board {
     $MICROPY_AUTOBUILD_MAKE BOARD=$board BUILD=$build_dir && copy_artefacts $dest_dir $descr $fw_tag $build_dir $@
     rm -rf $build_dir
 
-    # Query variants from board.json and build them. Ignore the special "idf3"
+    # Query variants from board.json and build them. Ignore the special "IDF3"
     # variant for ESP32 boards (this allows the downloads page to still have
     # the idf3 files for older releases that used to be explicitly built).
-    for variant in `cat $board_json | python3 -c "import json,sys; print(' '.join(v for v in json.load(sys.stdin).get('variants', {}).keys() if v != 'idf3'))"`; do
+    for variant in `cat $board_json | python3 -c "import json,sys; print(' '.join(v for v in json.load(sys.stdin).get('variants', {}).keys() if v != 'IDF3'))"`; do
         local variant_build_dir=$build_dir-$variant
         echo "building variant $descr $board $variant"
         $MICROPY_AUTOBUILD_MAKE BOARD=$board BOARD_VARIANT=$variant BUILD=$variant_build_dir && copy_artefacts $dest_dir $descr-$variant $fw_tag $variant_build_dir $@