diff --git a/STM32F1/libraries/Wire/Wire.cpp b/STM32F1/libraries/Wire/Wire.cpp
index 3f5f161..a026e2e 100644
--- a/STM32F1/libraries/Wire/Wire.cpp
+++ b/STM32F1/libraries/Wire/Wire.cpp
@@ -97,8 +97,10 @@ void HardWire::setClock(uint32_t frequencyHz)
 			dev_flags &= ~I2C_FAST_MODE;// clear FAST_MODE bit
 			break;
 	}
-	i2c_disable(sel_hard);
-	i2c_master_enable(sel_hard, dev_flags);
+	if (sel_hard->regs->CR1 & I2C_CR1_PE){
+	    i2c_disable(sel_hard);
+	    i2c_master_enable(sel_hard, dev_flags);
+	}
 }
 
 HardWire Wire(1);