diff --git a/ir_Aiwa.cpp b/ir_Aiwa.cpp
index f56aa99..bd5ba89 100644
--- a/ir_Aiwa.cpp
+++ b/ir_Aiwa.cpp
@@ -38,7 +38,7 @@ void  IRsend::sendAiwaRCT501 (int code)
 	space(AIWA_RC_T501_HDR_SPACE);
 
 	// Send "pre" data
-	for (unsigned long  mask = 1 << (26 - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (26 - 1);  mask;  mask >>= 1) {
 		mark(AIWA_RC_T501_BIT_MARK);
 		if (pre & mask)  space(AIWA_RC_T501_ONE_SPACE) ;
 		else             space(AIWA_RC_T501_ZERO_SPACE) ;
diff --git a/ir_Denon.cpp b/ir_Denon.cpp
index 7c9b075..c54e286 100644
--- a/ir_Denon.cpp
+++ b/ir_Denon.cpp
@@ -41,7 +41,7 @@ void  IRsend::sendDenon (unsigned long data,  int nbits)
 	space(HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark (BIT_MARK);
 			space(ONE_SPACE);
diff --git a/ir_Dish.cpp b/ir_Dish.cpp
index 387b163..3dad813 100644
--- a/ir_Dish.cpp
+++ b/ir_Dish.cpp
@@ -39,7 +39,7 @@ void  IRsend::sendDISH (unsigned long data,  int nbits)
 	mark(DISH_HDR_MARK);
 	space(DISH_HDR_SPACE);
 
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(DISH_BIT_MARK);
 			space(DISH_ONE_SPACE);
diff --git a/ir_JVC.cpp b/ir_JVC.cpp
index 123c20e..eeec20f 100644
--- a/ir_JVC.cpp
+++ b/ir_JVC.cpp
@@ -36,7 +36,7 @@ void  IRsend::sendJVC (unsigned long data,  int nbits,  bool repeat)
 	}
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(JVC_BIT_MARK);
 			space(JVC_ONE_SPACE);
diff --git a/ir_NEC.cpp b/ir_NEC.cpp
index 8da46e8..3b49321 100644
--- a/ir_NEC.cpp
+++ b/ir_NEC.cpp
@@ -29,7 +29,7 @@ void  IRsend::sendNEC (unsigned long data,  int nbits)
 	space(NEC_HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(NEC_BIT_MARK);
 			space(NEC_ONE_SPACE);
diff --git a/ir_Panasonic.cpp b/ir_Panasonic.cpp
index d3b471a..dc0dd73 100644
--- a/ir_Panasonic.cpp
+++ b/ir_Panasonic.cpp
@@ -28,14 +28,14 @@ void  IRsend::sendPanasonic (unsigned int address,  unsigned long data)
 	space(PANASONIC_HDR_SPACE);
 
 	// Address
-	for (unsigned long  mask = 1 << (16 - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (16 - 1);  mask;  mask >>= 1) {
 		mark(PANASONIC_BIT_MARK);
 		if (address & mask)  space(PANASONIC_ONE_SPACE) ;
 		else                 space(PANASONIC_ZERO_SPACE) ;
     }
 
 	// Data
-	for (unsigned long  mask = 1 << (32 - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (32 - 1);  mask;  mask >>= 1) {
         mark(PANASONIC_BIT_MARK);
         if (data & mask)  space(PANASONIC_ONE_SPACE) ;
         else              space(PANASONIC_ZERO_SPACE) ;
diff --git a/ir_RC5_RC6.cpp b/ir_RC5_RC6.cpp
index 1a9576d..e59e3c0 100644
--- a/ir_RC5_RC6.cpp
+++ b/ir_RC5_RC6.cpp
@@ -64,7 +64,7 @@ void  IRsend::sendRC5 (unsigned long data,  int nbits)
 	mark(RC5_T1);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			space(RC5_T1); // 1 is space, then mark
 			mark(RC5_T1);
@@ -141,7 +141,7 @@ void  IRsend::sendRC6 (unsigned long data,  int nbits)
 	space(RC6_T1);
 
 	// Data
-	for (unsigned long  i = 1, mask = 1 << (nbits - 1);  mask;  i++, mask >>= 1) {
+	for (unsigned long  i = 1, mask = 1UL << (nbits - 1);  mask;  i++, mask >>= 1) {
 		// The fourth bit we send is a "double width trailer bit"
 		int  t = (i == 4) ? (RC6_T1 * 2) : (RC6_T1) ;
 		if (data & mask) {
diff --git a/ir_Samsung.cpp b/ir_Samsung.cpp
index 65452f2..224487d 100644
--- a/ir_Samsung.cpp
+++ b/ir_Samsung.cpp
@@ -29,7 +29,7 @@ void  IRsend::sendSAMSUNG (unsigned long data,  int nbits)
 	space(SAMSUNG_HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(SAMSUNG_BIT_MARK);
 			space(SAMSUNG_ONE_SPACE);
diff --git a/ir_Sharp.cpp b/ir_Sharp.cpp
index 13f8a53..73462c5 100644
--- a/ir_Sharp.cpp
+++ b/ir_Sharp.cpp
@@ -40,7 +40,7 @@ void  IRsend::sendSharpRaw (unsigned long data,  int nbits)
 	// Sending codes in bursts of 3 (normal, inverted, normal) makes transmission
 	// much more reliable. That's the exact behaviour of CD-S6470 remote control.
 	for (int n = 0;  n < 3;  n++) {
-		for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+		for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 			if (data & mask) {
 				mark(SHARP_BIT_MARK);
 				space(SHARP_ONE_SPACE);
diff --git a/ir_Sony.cpp b/ir_Sony.cpp
index e01df55..31e67cf 100644
--- a/ir_Sony.cpp
+++ b/ir_Sony.cpp
@@ -29,7 +29,7 @@ void  IRsend::sendSony (unsigned long data,  int nbits)
 	space(SONY_HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(SONY_ONE_MARK);
 			space(SONY_HDR_SPACE);
diff --git a/ir_Template.cpp b/ir_Template.cpp
index 474d777..eee2b0b 100644
--- a/ir_Template.cpp
+++ b/ir_Template.cpp
@@ -126,7 +126,7 @@ void  IRsend::sendShuzu (unsigned long data,  int nbits)
 	space(HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark (BIT_MARK);
 			space(ONE_SPACE);
diff --git a/ir_Whynter.cpp b/ir_Whynter.cpp
index 2165cb7..a830562 100644
--- a/ir_Whynter.cpp
+++ b/ir_Whynter.cpp
@@ -34,7 +34,7 @@ void  IRsend::sendWhynter (unsigned long data,  int nbits)
 	space(WHYNTER_HDR_SPACE);
 
 	// Data
-	for (unsigned long  mask = 1 << (nbits - 1);  mask;  mask >>= 1) {
+	for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
 		if (data & mask) {
 			mark(WHYNTER_ONE_MARK);
 			space(WHYNTER_ONE_SPACE);