diff --git a/drivers/include/saul.h b/drivers/include/saul.h
index b8a62d145e..7cace775a1 100644
--- a/drivers/include/saul.h
+++ b/drivers/include/saul.h
@@ -104,6 +104,7 @@ enum {
     SAUL_SENSE_PM          = 0x96,     /**< sensor: particulate matter */
     SAUL_SENSE_CAPACITANCE = 0x97,     /**< sensor: capacitance */
     SAUL_SENSE_VOLTAGE     = 0x98,     /**< sensor: voltage */
+    SAUL_SENSE_PH          = 0x99,     /**< sensor: pH */
     SAUL_CLASS_ANY         = 0xff      /**< any device - wildcard */
     /* extend this list as needed... */
 };
diff --git a/drivers/saul/saul_str.c b/drivers/saul/saul_str.c
index 45c5b4eaaa..12150c0e9d 100644
--- a/drivers/saul/saul_str.c
+++ b/drivers/saul/saul_str.c
@@ -61,6 +61,7 @@ const char *saul_class_to_str(const uint8_t class_id)
         case SAUL_SENSE_PM:          return "SENSE_PM";
         case SAUL_SENSE_CAPACITANCE: return "SENSE_CAPACITANCE";
         case SAUL_SENSE_VOLTAGE:     return "SENSE_VOLTAGE";
+        case SAUL_SENSE_PH:          return "SENSE_PH";
         case SAUL_CLASS_ANY:         return "CLASS_ANY";
         default:                     return "CLASS_UNKNOWN";
     }
diff --git a/sys/include/phydat.h b/sys/include/phydat.h
index d56f968ed1..60a96775d4 100644
--- a/sys/include/phydat.h
+++ b/sys/include/phydat.h
@@ -97,6 +97,8 @@ enum {
     UNIT_DBM,       /**< decibel-milliwatts */
     UNIT_COULOMB,   /**< coulomb */
     UNIT_F,         /**< Farad */
+    /* electrochemical */
+    UNIT_PH,        /**< pH  */
     /* pressure */
     UNIT_BAR,       /**< Beer? */
     UNIT_PA,        /**< Pascal */
diff --git a/sys/phydat/phydat_str.c b/sys/phydat/phydat_str.c
index ff9e9ad8dc..1d847ac624 100644
--- a/sys/phydat/phydat_str.c
+++ b/sys/phydat/phydat_str.c
@@ -104,6 +104,7 @@ const char *phydat_unit_to_str(uint8_t unit)
         case UNIT_COULOMB:  return "C";
         case UNIT_GPM3:     return "g/m^3";
         case UNIT_F:        return "F";
+        case UNIT_PH:       return "pH";
         default:            return "";
     }
 }