diff --git a/src/ClickEncoder.cpp b/src/ClickEncoder.cpp
index 3684db3..c16e099 100644
--- a/src/ClickEncoder.cpp
+++ b/src/ClickEncoder.cpp
@@ -10,6 +10,18 @@
 // ----------------------------------------------------------------------------
 
 #include "ClickEncoder.h"
+#if defined(ESP8266)
+#  if defined(IRAM_ATTR)
+#    define CLICK_ENCODER_ISR_ATTR IRAM_ATTR
+#  elif defined(ICACHE_RAM_ATTR)
+#    define CLICK_ENCODER_ISR_ATTR ICACHE_RAM_ATTR
+#  else
+#    error "ClickEncoder requires IRAM_ATTR or ICACHE_RAM_ATTR on ESP8266"
+#  endif
+#else
+#  define CLICK_ENCODER_ISR_ATTR
+#endif
+
 
 // ----------------------------------------------------------------------------
 // Button configuration (values for 1ms timer service calls)
@@ -112,7 +124,7 @@ AnalogButton::AnalogButton(int8_t BTN, int16_t rangeLow, int16_t rangeHigh) : Cl
 // ----------------------------------------------------------------------------
 // call this every 1 millisecond via timer ISR
 //
-void ClickEncoder::service(void)
+void CLICK_ENCODER_ISR_ATTR ClickEncoder::service(void)
 {
   bool moved = false;
 
@@ -170,24 +182,29 @@ void ClickEncoder::service(void)
     }
   }
 }
-  // handle button
-  //
 #ifndef WITHOUT_BUTTON
+#if defined(ESP8266)
+  if (!analogInput) {
+    serviceButton();
+  }
+#else
+  serviceButton();
+#endif
+#endif
+
+}
+
+#ifndef WITHOUT_BUTTON
+void CLICK_ENCODER_ISR_ATTR ClickEncoder::serviceButton(void)
+{
   unsigned long currentMillis = millis();
   unsigned long millisSinceLastCheck = currentMillis - lastButtonCheck;
-  if ((pinBTN > 0 || (pinBTN == 0 && buttonOnPinZeroEnabled))        // check button only, if a pin has been provided
-      && (millisSinceLastCheck >= ENC_BUTTONINTERVAL))            // checking button is sufficient every 10-30ms
-  { 
+  if ((pinBTN > 0 || (pinBTN == 0 && buttonOnPinZeroEnabled))
+      && (millisSinceLastCheck >= ENC_BUTTONINTERVAL))
+  {
     lastButtonCheck = currentMillis;
 
     bool pinRead = getPinState();
-	
-											   
-					 
-																						  
-					  
-	   
-	 
 
     if (pinRead == !pinsActive) { // key is now up
       if (keyDownTicks > 1) {               //Make sure key was down through 1 complete tick to prevent random transients from registering as click
@@ -211,14 +228,14 @@ void ClickEncoder::service(void)
 
       keyDownTicks = 0;
     }
-    
+
     if (pinRead == pinsActive) { // key is down
       if ((keyDownTicks > (buttonHoldTime)) && (buttonHeldEnabled)) {
         button = Held;
       }
       keyDownTicks += millisSinceLastCheck;
     }
-  
+
     if (doubleClickTicks > 0) {
       doubleClickTicks -= (uint16_t)constrain(min(millisSinceLastCheck, (unsigned long)doubleClickTicks), 0, 65536);
       if (doubleClickTicks == 0) {
@@ -226,9 +243,8 @@ void ClickEncoder::service(void)
       }
     }
   }
-#endif // WITHOUT_BUTTON
-
 }
+#endif
 
 // ----------------------------------------------------------------------------
 
@@ -289,6 +305,11 @@ void ClickEncoder::resetEncoder(void)
 #ifndef WITHOUT_BUTTON
 ClickEncoder::Button ClickEncoder::getButton(void)
 {
+#if defined(ESP8266)
+  if (analogInput) {
+    serviceButton();
+  }
+#endif
   noInterrupts();
   ClickEncoder::Button ret = button;
   if (button != ClickEncoder::Held && ret != ClickEncoder::Open) {
@@ -299,7 +320,7 @@ ClickEncoder::Button ClickEncoder::getButton(void)
   return ret;
 }
 
-bool ClickEncoder::getPinState() {
+bool CLICK_ENCODER_ISR_ATTR ClickEncoder::getPinState() {
   bool pinState;
   if (analogInput) {
     int16_t pinValue = analogRead(pinBTN);
@@ -311,3 +332,4 @@ bool ClickEncoder::getPinState() {
 }
 
 #endif
+#undef CLICK_ENCODER_ISR_ATTR
diff --git a/src/ClickEncoder.h b/src/ClickEncoder.h
index 9bbe856..e82b9d9 100644
--- a/src/ClickEncoder.h
+++ b/src/ClickEncoder.h
@@ -173,6 +173,7 @@ class ClickEncoder
   unsigned long lastButtonCheck = 0;
   int16_t anlogActiveRangeLow = 0;
   int16_t anlogActiveRangeHigh = 0;
+  void serviceButton(void);
   bool getPinState();
 #endif
 };
diff --git a/test/esp8266_analog_button_test.cpp b/test/esp8266_analog_button_test.cpp
new file mode 100644
index 0000000..324bc33
--- /dev/null
+++ b/test/esp8266_analog_button_test.cpp
@@ -0,0 +1,74 @@
+#include <assert.h>
+
+#include "ClickEncoder.h"
+
+static unsigned long fakeMillis;
+static int fakeAnalogValue;
+static int fakeDigitalValue;
+static unsigned int analogReadCalls;
+static unsigned int digitalReadCalls;
+
+unsigned long millis(void)
+{
+  return fakeMillis;
+}
+
+int analogRead(uint8_t)
+{
+  ++analogReadCalls;
+  return fakeAnalogValue;
+}
+
+int digitalRead(uint8_t)
+{
+  ++digitalReadCalls;
+  return fakeDigitalValue;
+}
+
+void pinMode(uint8_t, uint8_t)
+{
+}
+
+void noInterrupts(void)
+{
+}
+
+void interrupts(void)
+{
+}
+
+int main(void)
+{
+  fakeAnalogValue = 150;
+  AnalogButton analogButton(1, 100, 200);
+
+#if defined(ESP8266)
+  fakeMillis = 10;
+  assert(analogButton.getButton() == ClickEncoder::Open);
+  assert(analogReadCalls == 1);
+
+  fakeMillis = 20;
+  analogButton.service();
+  assert(analogReadCalls == 1);
+
+  fakeAnalogValue = 900;
+  assert(analogButton.getButton() == ClickEncoder::Open);
+  assert(analogReadCalls == 2);
+
+  fakeMillis = 410;
+  assert(analogButton.getButton() == ClickEncoder::Clicked);
+  assert(analogReadCalls == 3);
+
+  fakeDigitalValue = LOW;
+  DigitalButton digitalButton(1);
+  fakeMillis = 10;
+  digitalButton.service();
+  assert(digitalReadCalls == 1);
+#else
+  fakeMillis = 10;
+  analogButton.service();
+  assert(analogReadCalls == 1);
+#endif
+
+  return 0;
+}
diff --git a/test/support/Arduino.h b/test/support/Arduino.h
new file mode 100644
index 0000000..e32fc98
--- /dev/null
+++ b/test/support/Arduino.h
@@ -0,0 +1,21 @@
+#ifndef TEST_SUPPORT_ARDUINO_H
+#define TEST_SUPPORT_ARDUINO_H
+
+#include <stdint.h>
+
+#define LOW 0x0
+#define HIGH 0x1
+#define INPUT 0x0
+#define INPUT_PULLUP 0x2
+
+unsigned long millis(void);
+int analogRead(uint8_t pin);
+int digitalRead(uint8_t pin);
+void pinMode(uint8_t pin, uint8_t mode);
+void noInterrupts(void);
+void interrupts(void);
+
+#define min(a, b) ((a) < (b) ? (a) : (b))
+#define constrain(value, lower, upper) ((value) < (lower) ? (lower) : ((value) > (upper) ? (upper) : (value)))
+
+#endif