diff --git a/libraries/I2S/src/I2S.cpp b/libraries/I2S/src/I2S.cpp
index 00837e202..2628d5870 100644
--- a/libraries/I2S/src/I2S.cpp
+++ b/libraries/I2S/src/I2S.cpp
@@ -38,9 +38,20 @@ static I2SDevice_SAMD21G18x i2sd(*I2S);
 #include "I2S.h"
 
 #ifdef USE_TINYUSB
-// For Serial when selecting TinyUSB
+// For Serial when selecting TinyUSB (also causes the Arduino builder to link
+// the TinyUSB library). Outside PlatformIO this include must stay plain and
+// unconditional: the Arduino builder discovers the library from it, and its
+// dependency-detection pass cannot parse a __has_include() expression.
+#ifdef PLATFORMIO
+// PlatformIO does not give framework-bundled libraries the lib_deps include
+// paths, so the header can be unreachable here; skip it instead of failing.
+#if !defined(__has_include) || __has_include(<Adafruit_TinyUSB.h>)
 #include <Adafruit_TinyUSB.h>
 #endif
+#else
+#include <Adafruit_TinyUSB.h>
+#endif
+#endif
 
 
 int I2SClass::_beginCount = 0;
diff --git a/libraries/SAMD_AnalogCorrection/src/SAMD_AnalogCorrection.cpp b/libraries/SAMD_AnalogCorrection/src/SAMD_AnalogCorrection.cpp
index e39ab43e3..7deeaf0bd 100644
--- a/libraries/SAMD_AnalogCorrection/src/SAMD_AnalogCorrection.cpp
+++ b/libraries/SAMD_AnalogCorrection/src/SAMD_AnalogCorrection.cpp
@@ -20,9 +20,20 @@
 #include "SAMD_AnalogCorrection.h"
 
 #ifdef USE_TINYUSB
-// For Serial when selecting TinyUSB
+// For Serial when selecting TinyUSB (also causes the Arduino builder to link
+// the TinyUSB library). Outside PlatformIO this include must stay plain and
+// unconditional: the Arduino builder discovers the library from it, and its
+// dependency-detection pass cannot parse a __has_include() expression.
+#ifdef PLATFORMIO
+// PlatformIO does not give framework-bundled libraries the lib_deps include
+// paths, so the header can be unreachable here; skip it instead of failing.
+#if !defined(__has_include) || __has_include(<Adafruit_TinyUSB.h>)
 #include <Adafruit_TinyUSB.h>
 #endif
+#else
+#include <Adafruit_TinyUSB.h>
+#endif
+#endif
 
 void analogReadCorrection (int offset, uint16_t gain)
 {
diff --git a/libraries/SPI/SPI.cpp b/libraries/SPI/SPI.cpp
index 0393752d7..42c0564d5 100644
--- a/libraries/SPI/SPI.cpp
+++ b/libraries/SPI/SPI.cpp
@@ -23,9 +23,20 @@
 #include <assert.h>
 
 #ifdef USE_TINYUSB
-// For Serial when selecting TinyUSB
+// For Serial when selecting TinyUSB (also causes the Arduino builder to link
+// the TinyUSB library). Outside PlatformIO this include must stay plain and
+// unconditional: the Arduino builder discovers the library from it, and its
+// dependency-detection pass cannot parse a __has_include() expression.
+#ifdef PLATFORMIO
+// PlatformIO does not give framework-bundled libraries the lib_deps include
+// paths, so the header can be unreachable here; skip it instead of failing.
+#if !defined(__has_include) || __has_include(<Adafruit_TinyUSB.h>)
 #include <Adafruit_TinyUSB.h>
 #endif
+#else
+#include <Adafruit_TinyUSB.h>
+#endif
+#endif
 
 #define SPI_IMODE_NONE   0
 #define SPI_IMODE_EXTINT 1
diff --git a/libraries/Servo/src/samd/Servo.cpp b/libraries/Servo/src/samd/Servo.cpp
index ba07e70a7..5cf289978 100644
--- a/libraries/Servo/src/samd/Servo.cpp
+++ b/libraries/Servo/src/samd/Servo.cpp
@@ -22,9 +22,20 @@
 #include <Servo.h>
 
 #ifdef USE_TINYUSB
-// For Serial when selecting TinyUSB
+// For Serial when selecting TinyUSB (also causes the Arduino builder to link
+// the TinyUSB library). Outside PlatformIO this include must stay plain and
+// unconditional: the Arduino builder discovers the library from it, and its
+// dependency-detection pass cannot parse a __has_include() expression.
+#ifdef PLATFORMIO
+// PlatformIO does not give framework-bundled libraries the lib_deps include
+// paths, so the header can be unreachable here; skip it instead of failing.
+#if !defined(__has_include) || __has_include(<Adafruit_TinyUSB.h>)
 #include <Adafruit_TinyUSB.h>
 #endif
+#else
+#include <Adafruit_TinyUSB.h>
+#endif
+#endif
 
 #if defined(__SAMD51__)
  // Different prescalers depending on FCPU (avoid overflowing 16-bit counter)
diff --git a/libraries/Wire/Wire.cpp b/libraries/Wire/Wire.cpp
index da9732c59..f79ad0038 100644
--- a/libraries/Wire/Wire.cpp
+++ b/libraries/Wire/Wire.cpp
@@ -25,9 +25,20 @@ extern "C" {
 #include <wiring_private.h>
 
 #ifdef USE_TINYUSB
-// For Serial when selecting TinyUSB
+// For Serial when selecting TinyUSB (also causes the Arduino builder to link
+// the TinyUSB library). Outside PlatformIO this include must stay plain and
+// unconditional: the Arduino builder discovers the library from it, and its
+// dependency-detection pass cannot parse a __has_include() expression.
+#ifdef PLATFORMIO
+// PlatformIO does not give framework-bundled libraries the lib_deps include
+// paths, so the header can be unreachable here; skip it instead of failing.
+#if !defined(__has_include) || __has_include(<Adafruit_TinyUSB.h>)
 #include <Adafruit_TinyUSB.h>
 #endif
+#else
+#include <Adafruit_TinyUSB.h>
+#endif
+#endif
 
 #include "Wire.h"