diff --git a/builder/frameworks/_bare_arm.py b/builder/frameworks/_bare_arm.py
index cc62592..277d58d 100644
--- a/builder/frameworks/_bare_arm.py
+++ b/builder/frameworks/_bare_arm.py
@@ -34,8 +34,7 @@
         "-ffunction-sections",  # place each function in its own section
         "-fdata-sections",
         "-mthumb",
-        "-nostdlib",
-        "-fsingle-precision-constant"
+        "-nostdlib"
     ],
 
     CXXFLAGS=[
@@ -56,8 +55,7 @@
         "-Os",
         "-Wl,--gc-sections,--relax",
         "-mthumb",
-        "-Wl,--defsym=__rtc_localtime=$UNIX_TIME",
-        "-fsingle-precision-constant"
+        "-Wl,--defsym=__rtc_localtime=$UNIX_TIME"
     ],
 
     LIBS=["m", "stdc++"]
@@ -91,3 +89,17 @@
             "-mcpu=%s" % env.BoardConfig().get("build.cpu")
         ]
     )
+
+if env.BoardConfig().get("build.core", "") != "teensy4":
+    env.Append(
+        ASFLAGS=[
+            "-mno-unaligned-access",
+        ],
+        CCFLAGS=[
+            "-mno-unaligned-access",
+            "-fsingle-precision-constant"
+        ],
+        LINKFLAGS=[
+            "-fsingle-precision-constant"
+        ]
+    )
diff --git a/builder/frameworks/arduino.py b/builder/frameworks/arduino.py
index 58111bb..3cafc98 100644
--- a/builder/frameworks/arduino.py
+++ b/builder/frameworks/arduino.py
@@ -145,8 +145,7 @@
             "-fdata-sections",
             "-mthumb",
             "-mcpu=%s" % env.BoardConfig().get("build.cpu"),
-            "-nostdlib",
-            "-fsingle-precision-constant"
+            "-nostdlib"
         ],
 
         CXXFLAGS=[
diff --git a/examples/arduino-blink/.gitignore b/examples/arduino-blink/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/arduino-blink/.gitignore
+++ b/examples/arduino-blink/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/arduino-blink/platformio.ini b/examples/arduino-blink/platformio.ini
index 84d9b90..0b58105 100644
--- a/examples/arduino-blink/platformio.ini
+++ b/examples/arduino-blink/platformio.ini
@@ -12,7 +12,7 @@ platform = teensy
 framework = arduino
 board = teensy2
 
-[env:teensy 2pp]
+[env:teensy2pp]
 platform = teensy
 framework = arduino
 board = teensy2pp
diff --git a/examples/arduino-hid-usb-mouse/.gitignore b/examples/arduino-hid-usb-mouse/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/arduino-hid-usb-mouse/.gitignore
+++ b/examples/arduino-hid-usb-mouse/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/arduino-internal-libs/.gitignore b/examples/arduino-internal-libs/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/arduino-internal-libs/.gitignore
+++ b/examples/arduino-internal-libs/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/mbed-blink/.gitignore b/examples/mbed-blink/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/mbed-blink/.gitignore
+++ b/examples/mbed-blink/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/mbed-dsp/.gitignore b/examples/mbed-dsp/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/mbed-dsp/.gitignore
+++ b/examples/mbed-dsp/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/mbed-events/.gitignore b/examples/mbed-events/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/mbed-events/.gitignore
+++ b/examples/mbed-events/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/examples/mbed-events/platformio.ini b/examples/mbed-events/platformio.ini
index 79a2239..e888ac2 100644
--- a/examples/mbed-events/platformio.ini
+++ b/examples/mbed-events/platformio.ini
@@ -7,7 +7,7 @@
 ; Please visit documentation for the other options and examples
 ; https://docs.platformio.org/page/projectconf.html
 
-[env:teensy31 events]
+[env:teensy31]
 platform = teensy
 framework = mbed
 board = teensy31
diff --git a/examples/mbed-serial/.gitignore b/examples/mbed-serial/.gitignore
index 6c69f4c..03f4a3c 100644
--- a/examples/mbed-serial/.gitignore
+++ b/examples/mbed-serial/.gitignore
@@ -1,2 +1 @@
-.pioenvs
-.piolibdeps
+.pio
diff --git a/platform.json b/platform.json
index 7e13e41..f883723 100644
--- a/platform.json
+++ b/platform.json
@@ -19,7 +19,7 @@
     "type": "git",
     "url": "https://github.com/platformio/platform-teensy.git"
   },
-  "version": "4.17.0",
+  "version": "4.18.0",
   "frameworks": {
     "arduino": {
       "package": "framework-arduinoteensy",
@@ -43,16 +43,22 @@
       "optionalVersions": [">=1.60301.0,<1.80000.0"]
     },
     "toolchain-gccarmnoneeabi": {
+      "type": "toolchain",
+      "optional": true,
+      "owner": "platformio",
+      "version": "~1.80201.0"
+    },
+    "toolchain-gccarmnoneeabi-teensy": {
       "type": "toolchain",
       "optional": false,
       "owner": "platformio",
-      "version": "~1.50401.0"
+      "version": "~1.110301.0"
     },
     "framework-arduinoteensy": {
       "type": "framework",
       "optional": true,
       "owner": "platformio",
-      "version": "~1.157.0"
+      "version": "~1.158.0"
     },
     "framework-mbed": {
       "type": "framework",
diff --git a/platform.py b/platform.py
index 1e04d35..b85b655 100644
--- a/platform.py
+++ b/platform.py
@@ -32,16 +32,18 @@ def configure_default_packages(self, variables, targets):
                 del self.packages[del_toolchain]
 
         frameworks = variables.get("pioframework", [])
-        if "mbed" in frameworks:
-            self.packages["toolchain-gccarmnoneeabi"][
-                "version"] = ">=1.60301.0,<1.80000.0"
-        elif "zephyr" in frameworks:
+        if "arduino" in frameworks:
+            self.packages.pop("toolchain-gccarmnoneeabi", None)
+        else:
+            self.packages["toolchain-gccarmnoneeabi"]["optional"] = False
+            self.packages.pop("toolchain-gccarmnoneeabi-teensy", None)
+
+        if "zephyr" in frameworks:
             for p in self.packages:
                 if p in ("tool-cmake", "tool-dtc", "tool-ninja"):
                     self.packages[p]["optional"] = False
             if not IS_WINDOWS:
                 self.packages["tool-gperf"]["optional"] = False
-            self.packages["toolchain-gccarmnoneeabi"]["version"] = "~1.80201.0"
         elif "arduino" in frameworks and board_config.get("build.core", "") == "teensy4":
             self.packages["tool-teensy"]["optional"] = False