diff --git a/platformio.ini b/platformio.ini
index bb4eab309..3ba1c8891 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -65,6 +65,8 @@ check_flags =
 ; the Web interface is built seperately
 [env:ci]
 extends = espressi32_base
+; stay on platform 6.3.2 until heap issue is solved
+platform = espressif32@6.3.2
 extra_scripts = scripts/rename_fw.py
 board = esp32dev
 board_build.partitions = esp32_partition_4M.csv
@@ -85,6 +87,8 @@ build_unflags = ${common.unbuild_flags}
 
 [env:esp32_4M]
 extends = espressi32_base
+; stay on platform 6.3.2 until heap issue is solved
+platform = espressif32@6.3.2
 board = esp32dev
 board_upload.flash_size = 4MB
 board_build.partitions = esp32_partition_4M.csv
@@ -92,6 +96,8 @@ build_flags = ${common.build_flags} -Os
 
 [env:esp32_4Mplus]
 extends = espressi32_base
+; stay on platform 6.3.2 until heap issue is solved
+platform = espressif32@6.3.2
 board = esp32dev
 board_upload.flash_size = 4MB
 board_build.partitions = esp32_asym_partition_4M.csv
@@ -99,6 +105,8 @@ build_flags = ${common.build_flags}
 
 [env:esp32_16M]
 extends = espressi32_base
+; stay on platform 6.3.2 until heap issue is solved
+platform = espressif32@6.3.2
 board = esp32dev
 board_upload.flash_size = 16MB
 board_build.partitions = esp32_partition_16M.csv