diff --git a/lib/LiquidCrystal_I2C/LiquidCrystal_I2C.cpp b/lib/LiquidCrystal_I2C/LiquidCrystal_I2C.cpp
index e64c54b..a673704 100644
--- a/lib/LiquidCrystal_I2C/LiquidCrystal_I2C.cpp
+++ b/lib/LiquidCrystal_I2C/LiquidCrystal_I2C.cpp
@@ -65,10 +65,10 @@ void LiquidCrystal_I2C::begin_priv(uint8_t dotsize) {
     // according to datasheet, we need at least 40ms after power rises above 2.7V
     // before sending commands. Nucleo can turn on way befer 4.5V so we'll wait
     // 50
-    wait_ms(50);
+    wait_us(50000);
     // Now we pull both RS and R/W low to begin commands
     expanderWrite(_backlightval); // reset expanderand turn backlight off (Bit 8 =1)
-    wait_ms(1000);
+    wait_us(1000000);
     // put the LCD into 4 bit mode
     // this is according to the hitachi HD44780 datasheet
     // figure 24, pg 46
diff --git a/lib/Print/Print.cpp b/lib/Print/Print.cpp
index a66e99c..ee13244 100644
--- a/lib/Print/Print.cpp
+++ b/lib/Print/Print.cpp
@@ -188,8 +188,8 @@ size_t Print::printFloat(double number, uint8_t digits)
 { 
   size_t n = 0;
   
-  if (isnan(number)) return print("nan");
-  if (isinf(number)) return print("inf");
+  if (std::isnan(number)) return print("nan");
+  if (std::isinf(number)) return print("inf");
   if (number > 4294967040.0) return print ("ovf");  // constant determined empirically
   if (number <-4294967040.0) return print ("ovf");  // constant determined empirically