diff --git a/cores/esp32/esp32-hal-i2c.c b/cores/esp32/esp32-hal-i2c.c
index a803d2879766398ddb234c3c47a6df60d2592485..ca7bc441b53cfa883906f87f719bd553cba94abd 100644
--- a/cores/esp32/esp32-hal-i2c.c
+++ b/cores/esp32/esp32-hal-i2c.c
@@ -67,7 +67,7 @@ i2c_err_t i2cAttachSCL(i2c_t * i2c, int8_t scl)
     if(i2c == NULL){
         return I2C_ERROR_DEV;
     }
-    pinMode(scl, OUTPUT);
+    pinMode(scl, OUTPUT_OPEN_DRAIN);
     pinMatrixOutAttach(scl, I2C_SCL_IDX(i2c->num), false, false);
     pinMatrixInAttach(scl, I2C_SCL_IDX(i2c->num), false);
     return I2C_ERROR_OK;