diff --git a/tools/i2c/i2c.cpp b/tools/i2c/i2c.cpp
index 4715c6e..7a0bbf4 100644
--- a/tools/i2c/i2c.cpp
+++ b/tools/i2c/i2c.cpp
@@ -200,7 +200,7 @@
 void I2CDevice::read(uint8_t addr, uint8_t& size, uint8_t* data, Mode mode)
 {
     checkIsOpen();
-    int ret;
+    int ret = -1;
     switch (mode)
     {
         case Mode::SMBUS:
@@ -261,7 +261,7 @@
                       Mode mode)
 {
     checkIsOpen();
-    int ret;
+    int ret = -1;
     switch (mode)
     {
         case Mode::SMBUS: