diff --git a/platformio.ini b/platformio.ini
index 1fc7291..a8022dc 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -20,11 +20,11 @@ default_envs =
 	ESP32
 	Nucleo-F411RE
 	Nucleo-F446RE
-	Teensy3.2
-	Teensy3.5
-	Teensy3.6
-	Teensy4.0
-	Teensy4.1
+	Teensy3_2
+	Teensy3_5
+	Teensy3_6
+	Teensy4_0
+	Teensy4_1
 src_dir = .
 include_dir = .
 
@@ -192,7 +192,7 @@ build_flags = -std=c++17  -Os -g2 -Wunused-variable -DDIAG_LOOPTIMES ; -DDIAG_IO
 monitor_speed = 115200
 monitor_echo = yes
 
-[env:Teensy3.2]
+[env:Teensy3_2]
 platform = teensy
 board = teensy31
 framework = arduino
@@ -200,7 +200,7 @@ build_flags = -std=c++17  -Os -g2
 lib_deps = ${env.lib_deps}
 lib_ignore = NativeEthernet
 
-[env:Teensy3.5]
+[env:Teensy3_5]
 platform = teensy
 board = teensy35
 framework = arduino
@@ -208,7 +208,7 @@ build_flags = -std=c++17  -Os -g2
 lib_deps = ${env.lib_deps}
 lib_ignore = NativeEthernet
 
-[env:Teensy3.6]
+[env:Teensy3_6]
 platform = teensy
 board = teensy36
 framework = arduino
@@ -216,7 +216,7 @@ build_flags = -std=c++17  -Os -g2
 lib_deps = ${env.lib_deps}
 lib_ignore = NativeEthernet
 
-[env:Teensy4.0]
+[env:Teensy4_0]
 platform = teensy
 board = teensy40
 framework = arduino
@@ -224,7 +224,7 @@ build_flags = -std=c++17  -Os -g2
 lib_deps = ${env.lib_deps}
 lib_ignore = NativeEthernet
 
-[env:Teensy4.1]
+[env:Teensy4_1]
 platform = teensy
 board = teensy41
 framework = arduino