diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index ff5c66080c8c..a98b52cb970b 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -35,9 +35,9 @@
  * platform data and other tables.
  */
 
-static inline int gpio_is_valid(int number)
+static inline bool gpio_is_valid(int number)
 {
-	return ((unsigned)number) < ARCH_NR_GPIOS;
+	return number >= 0 && number < ARCH_NR_GPIOS;
 }
 
 struct device;
@@ -212,7 +212,7 @@ extern void gpio_unexport(unsigned gpio);
 
 #else	/* !CONFIG_GPIOLIB */
 
-static inline int gpio_is_valid(int number)
+static inline bool gpio_is_valid(int number)
 {
 	/* only non-negative numbers are valid */
 	return number >= 0;
diff --git a/include/linux/gpio.h b/include/linux/gpio.h
index 32720baf70f1..0f8265f8e8c3 100644
--- a/include/linux/gpio.h
+++ b/include/linux/gpio.h
@@ -25,9 +25,9 @@ struct gpio_chip;
  * warning when something is wrongly called.
  */
 
-static inline int gpio_is_valid(int number)
+static inline bool gpio_is_valid(int number)
 {
-	return 0;
+	return false;
 }
 
 static inline int gpio_request(unsigned gpio, const char *label)