diff --git a/klippy/pins.py b/klippy/pins.py
index d70e3834..b424c4b9 100644
--- a/klippy/pins.py
+++ b/klippy/pins.py
@@ -42,6 +42,7 @@ MCU_PINS = {
     "atmega328": port_pins(5), "atmega328p": port_pins(5),
     "atmega644p": port_pins(4), "atmega1284p": port_pins(4),
     "at90usb1286": port_pins(6), "at90usb646": port_pins(6),
+    "atmega32u4": port_pins(6),
     "atmega1280": port_pins(12), "atmega2560": port_pins(12),
     "sam3x8e": port_pins(4, 32),
     "samd21g": port_pins(2, 32),
diff --git a/src/avr/Kconfig b/src/avr/Kconfig
index 18769d49..e0f407c0 100644
--- a/src/avr/Kconfig
+++ b/src/avr/Kconfig
@@ -26,6 +26,8 @@ choice
         bool "at90usb1286"
     config MACH_at90usb646
         bool "at90usb646"
+    config MACH_atmega32u4
+        bool "atmega32u4"
     config MACH_atmega1284p
         bool "atmega1284p"
     config MACH_atmega644p
@@ -47,14 +49,14 @@ config MCU
     default "atmega644p" if MACH_atmega644p
     default "at90usb1286" if MACH_at90usb1286
     default "at90usb646" if MACH_at90usb646
+    default "atmega32u4" if MACH_atmega32u4
     default "atmega1280" if MACH_atmega1280
     default "atmega2560" if MACH_atmega2560
 
 config AVRDUDE_PROTOCOL
     string
     default "wiring" if MACH_atmega2560
-    default "avr109" if MACH_at90usb1286
-    default "avr109" if MACH_at90usb646
+    default "avr109" if MACH_at90usb1286 || MACH_at90usb646 || MACH_atmega32u4
     default "arduino"
 
 choice
@@ -76,7 +78,7 @@ config CLOCK_FREQ
 
 config CLEAR_PRESCALER
     bool "Manually clear the CPU prescaler field at startup"
-    depends on MACH_at90usb1286 || MACH_at90usb646
+    depends on MACH_at90usb1286 || MACH_at90usb646 || MACH_atmega32u4
     default y
     help
          Some AVR chips ship with a "clock prescaler" that causes the
@@ -98,7 +100,7 @@ config AVR_WATCHDOG
     default y
 config AVR_USBSERIAL
     bool "Use USB for communication (instead of serial)"
-    depends on MACH_at90usb1286 || MACH_at90usb646
+    depends on MACH_at90usb1286 || MACH_at90usb646 || MACH_atmega32u4
     default y
 config AVR_SERIAL
     depends on !AVR_USBSERIAL
@@ -132,7 +134,7 @@ config SERIAL_PORT
     int
     default 3 if AVR_SERIAL_UART3
     default 2 if AVR_SERIAL_UART2
-    default 1 if MACH_at90usb1286 || MACH_at90usb646 || AVR_SERIAL_UART1
+    default 1 if MACH_at90usb1286 || MACH_at90usb646 || MACH_atmega32u4 || AVR_SERIAL_UART1
     default 0
 
 config SIMULAVR
diff --git a/src/avr/gpio.c b/src/avr/gpio.c
index b611fdbc..15da3d79 100644
--- a/src/avr/gpio.c
+++ b/src/avr/gpio.c
@@ -139,8 +139,10 @@ static const struct gpio_pwm_info pwm_regs[] PROGMEM = {
 #ifdef OCR1C
     { &OCR1C, &TCCR1A, &TCCR1B, 1<<COM1C1, 0 },
 #endif
+#ifdef OCR2A
     { &OCR2A, &TCCR2A, &TCCR2B, 1<<COM2A1, GP_8BIT|GP_AFMT },
     { &OCR2B, &TCCR2A, &TCCR2B, 1<<COM2B1, GP_8BIT|GP_AFMT },
+#endif
 #ifdef OCR3A
     { &OCR3A, &TCCR3A, &TCCR3B, 1<<COM3A1, 0 },
     { &OCR3B, &TCCR3A, &TCCR3B, 1<<COM3B1, 0 },
@@ -148,7 +150,7 @@ static const struct gpio_pwm_info pwm_regs[] PROGMEM = {
 #ifdef OCR3C
     { &OCR3C, &TCCR3A, &TCCR3B, 1<<COM3C1, 0 },
 #endif
-#ifdef OCR4A
+#ifdef OCR5A
     { &OCR4A, &TCCR4A, &TCCR4B, 1<<COM4A1, 0 },
     { &OCR4B, &TCCR4A, &TCCR4B, 1<<COM4B1, 0 },
     { &OCR4C, &TCCR4A, &TCCR4B, 1<<COM4C1, 0 },
@@ -175,6 +177,10 @@ static const uint8_t pwm_pins[ARRAY_SIZE(pwm_regs)] PROGMEM = {
     GPIO('B', 5), GPIO('B', 6), GPIO('B', 7),
     GPIO('B', 4), GPIO('D', 1),
     GPIO('C', 6), GPIO('C', 5), GPIO('C', 4),
+#elif CONFIG_MACH_atmega32u4
+    GPIO('B', 7), GPIO('D', 0),
+    GPIO('B', 5), GPIO('B', 6), GPIO('B', 7),
+    GPIO('C', 6), GPIO('C', 5), GPIO('C', 4),
 #elif CONFIG_MACH_atmega1280 || CONFIG_MACH_atmega2560
     GPIO('B', 7), GPIO('G', 5),
     GPIO('B', 5), GPIO('B', 6), GPIO('B', 7),
@@ -273,6 +279,10 @@ static const uint8_t adc_pins[] PROGMEM = {
 #elif CONFIG_MACH_at90usb1286 || CONFIG_MACH_at90usb646
     GPIO('F', 0), GPIO('F', 1), GPIO('F', 2), GPIO('F', 3),
     GPIO('F', 4), GPIO('F', 5), GPIO('F', 6), GPIO('F', 7),
+#elif CONFIG_MACH_atmega32u4
+    GPIO('F', 0), GPIO('F', 1), GPIO('F', 2), GPIO('F', 3),
+    GPIO('F', 4), GPIO('F', 5), GPIO('F', 6), GPIO('F', 7),
+    GPIO('D', 4), GPIO('D', 6), GPIO('D', 7), GPIO('B', 4),
 #elif CONFIG_MACH_atmega1280 || CONFIG_MACH_atmega2560
     GPIO('F', 0), GPIO('F', 1), GPIO('F', 2), GPIO('F', 3),
     GPIO('F', 4), GPIO('F', 5), GPIO('F', 6), GPIO('F', 7),
@@ -375,7 +385,7 @@ static const uint8_t MOSI = GPIO('B', 3), MISO = GPIO('B', 4);
 #elif CONFIG_MACH_atmega644p || CONFIG_MACH_atmega1284p
 static const uint8_t SS = GPIO('B', 4), SCK = GPIO('B', 7);
 static const uint8_t MOSI = GPIO('B', 5), MISO = GPIO('B', 6);
-#elif CONFIG_MACH_at90usb1286 || CONFIG_MACH_at90usb646 || CONFIG_MACH_atmega1280 || CONFIG_MACH_atmega2560
+#elif CONFIG_MACH_at90usb1286 || CONFIG_MACH_at90usb646 || CONFIG_MACH_atmega32u4 || CONFIG_MACH_atmega1280 || CONFIG_MACH_atmega2560
 static const uint8_t SS = GPIO('B', 0), SCK = GPIO('B', 1);
 static const uint8_t MOSI = GPIO('B', 2), MISO = GPIO('B', 3);
 #endif
diff --git a/src/avr/usbserial.c b/src/avr/usbserial.c
index 7405e534..e95ab040 100644
--- a/src/avr/usbserial.c
+++ b/src/avr/usbserial.c
@@ -178,18 +178,26 @@ usb_set_configure(void)
     UEIENX = 1<<TXINE;
 }
 
+#if CONFIG_MACH_at90usb1286
+#define UHWCON_Init ((1<<UIMOD) | (1<<UVREGE))
+#define PLLCSR_Init ((1<<PLLP2) | (1<<PLLP0) | (1<<PLLE))
+#elif CONFIG_MACH_at90usb646
+#define UHWCON_Init ((1<<UIMOD) | (1<<UVREGE))
+#define PLLCSR_Init ((1<<PLLP2) | (1<<PLLP1) | (1<<PLLE))
+#elif CONFIG_MACH_atmega32u4
+#define UHWCON_Init (1<<UVREGE)
+#define PLLCSR_Init ((1<<PINDIV) | (1<<PLLE))
+#endif
+
 void
 usbserial_init(void)
 {
     // Set USB controller to device mode
-    UHWCON = (1<<UIMOD) | (1<<UVREGE);
+    UHWCON = UHWCON_Init;
 
     // Enable USB clock
     USBCON = (1<<USBE) | (1<<FRZCLK);
-    if (CONFIG_MACH_at90usb1286)
-        PLLCSR = (1<<PLLP2) | (1<<PLLP0) | (1<<PLLE);
-    else
-        PLLCSR = (1<<PLLP2) | (1<<PLLP1) | (1<<PLLE);
+    PLLCSR = PLLCSR_Init;
     while (!(PLLCSR & (1<<PLOCK)))
         ;
     USBCON = (1<<USBE) | (1<<OTGPADE);