diff --git a/os/hal/ports/STM32/LLD/I2Cv2/i2c_lld.c b/os/hal/ports/STM32/LLD/I2Cv2/i2c_lld.c
index e0bc31979..991e77b01 100644
--- a/os/hal/ports/STM32/LLD/I2Cv2/i2c_lld.c
+++ b/os/hal/ports/STM32/LLD/I2Cv2/i2c_lld.c
@@ -844,8 +844,11 @@ void i2c_lld_start(I2CDriver *i2cp) {
 #endif
 
   /* Reset i2c peripheral, the TCIE bit will be handled separately.*/
-  dp->CR1 = i2cp->config->cr1 | I2C_CR1_ERRIE | I2C_CR1_NACKIE |
-            I2C_CR1_TXDMAEN | I2C_CR1_RXDMAEN;
+  dp->CR1 = i2cp->config->cr1 |
+#if STM32_I2C_USE_DMA == TRUE
+            I2C_CR1_TXDMAEN | I2C_CR1_RXDMAEN | /* Enable only if using DMA */
+#endif
+            I2C_CR1_ERRIE | I2C_CR1_NACKIE;
 
   /* Setup I2C parameters.*/
   dp->TIMINGR = i2cp->config->timingr;
diff --git a/readme.txt b/readme.txt
index 06857c225..3fe6a3d4c 100644
--- a/readme.txt
+++ b/readme.txt
@@ -134,6 +134,7 @@
 - HAL: Updated STM32F0xx headers to STM32CubeF0 version 1.3.0. Added support
        for STM32F030xC, STM32F070x6, STM32F070xB, STM32F091xC,
        STM32F098xx devices.
+- HAL: Fixed STM32 I2Cv2 DMA conflict (bug #671)(backported to 3.0.4).
 - HAL: Fixed I2S clock selection not working in STM32F4xx HAL (bug #667)
        (backported to 3.0.4 and 2.6.10).
 - HAL: Fixed differences in STM32F3 ADC macro definitions (bug #665)