diff --git a/stages/org.osbuild.chrony b/stages/org.osbuild.chrony
index 2274a47e..11cec065 100755
--- a/stages/org.osbuild.chrony
+++ b/stages/org.osbuild.chrony
@@ -54,6 +54,112 @@ def handle_leapsectz(chrony_conf_lines, timezone):
         chrony_conf_lines[:] = [f"leapsectz {timezone}"] + chrony_conf_lines
 
 
+def handle_refclocks(chrony_conf_lines, refclocks):
+    new_lines = []
+
+    for refclock in refclocks:
+        driver = refclock["driver"]
+        driver_name = driver["name"]
+        new_line = "refclock"
+        driver_options = ""
+        if driver_name == "PPS":
+            driver_options = handle_refclock_pps(driver)
+        elif driver_name == "SHM":
+            driver_options = handle_refclock_shm(driver)
+        elif driver_name == "SOCK":
+            driver_options = handle_refclock_sock(driver)
+        elif driver_name == "PHC":
+            driver_options = handle_refclock_phc(driver)
+        else:
+            # this should be caught by the schema
+            raise ValueError(f"unknown refclock driver {driver_name}")
+
+        new_line += " " + driver_options
+
+        # append general reflock options
+        refclock_options = []
+        poll = refclock.get("poll")
+        if poll is not None:
+            refclock_options.append(f"poll {poll}")
+
+        dpoll = refclock.get("dpoll")
+        if dpoll is not None:
+            refclock_options.append(f"dpoll {dpoll}")
+
+        offset = refclock.get("offset")
+        if offset is not None:
+            refclock_options.append(f"offset {offset}")
+
+        if refclock_options:
+            gen_options_str = " ".join(refclock_options)
+            new_line += " " + gen_options_str
+
+        new_lines.append(new_line)
+
+    chrony_conf_lines[:] = new_lines + chrony_conf_lines
+
+
+def handle_refclock_pps(driver):
+    device = driver["device"]
+    line = f"PPS {device}"
+
+    options = []
+    if driver.get("clear"):
+        options.append("clear")
+
+    if options:
+        options_str = ",".join(options)
+        line += f":{options_str}"
+
+    return line
+
+
+def handle_refclock_shm(driver):
+    segment = driver["segment"]
+    line = f"SHM {segment}"
+
+    options = []
+    perm = driver.get("perm")
+    if perm is not None:
+        options.append(f"perm={perm}")
+
+    if options:
+        options_str = ",".join(options)
+        line += f":{options_str}"
+
+    return line
+
+
+def handle_refclock_sock(driver):
+    path = driver["path"]
+    return f"SOCK {path}"
+
+
+def handle_refclock_phc(driver):
+    path = driver["path"]
+    line = f"PHC {path}"
+
+    options = []
+    if driver.get("nocrossts"):
+        options.append("nocrossts")
+    if driver.get("extpps"):
+        options.append("extpps")
+    pin = driver.get("pin")
+    if pin is not None:
+        options.append(f"pin={pin}")
+    channel = driver.get("channel")
+    if channel is not None:
+        options.append(f"channel={channel}")
+    if driver.get("clear"):
+        options.append("clear")
+
+    if options:
+        options_str = ",".join(options)
+        line += f":{options_str}"
+
+    return line
+
+
 def main(tree, options):
     timeservers = options.get("timeservers", [])
     servers = options.get("servers", [])
@@ -61,6 +167,8 @@ def main(tree, options):
     # therefore default to 'None' to distinguish these two cases.
     leapsectz = options.get("leapsectz", None)
 
+    refclocks = options.get("refclocks", [])
+
     with open(f"{tree}/etc/chrony.conf", encoding="utf8") as f:
         chrony_conf = f.read()
 
@@ -76,6 +184,8 @@ def main(tree, options):
         handle_servers(lines, servers)
     if leapsectz is not None:
         handle_leapsectz(lines, leapsectz)
+    if refclocks:
+        handle_refclocks(lines, refclocks)
 
     new_chrony_conf = "\n".join(lines)
 
diff --git a/stages/org.osbuild.chrony.meta.json b/stages/org.osbuild.chrony.meta.json
index caf72909..2229e87c 100644
--- a/stages/org.osbuild.chrony.meta.json
+++ b/stages/org.osbuild.chrony.meta.json
@@ -19,28 +19,19 @@
     "  - 'maxpoll'",
     "  - 'iburst' (defaults to true)",
     "  - 'prefer' (defaults to false)",
+    "",
     "The `leapsectz` option configures chrony behavior related to automatic checking",
     "of the next occurrence of the leap second, using the provided timezone. Its",
     "value is a string representing a timezone from the system tz database (e.g.",
     "'right/UTC'). If an empty string is provided, then all occurrences of",
     "`leapsectz` directive are removed from the configuration.",
-    "Constraints:",
-    "  - Exactly one of 'timeservers' or 'servers' options must be provided."
+    "",
+    "The refclock directive can be used to specify one or more hardware",
+    "reference clocks to be used as a time source."
   ],
   "schema": {
     "additionalProperties": false,
-    "oneOf": [
-      {
-        "required": [
-          "timeservers"
-        ]
-      },
-      {
-        "required": [
-          "servers"
-        ]
-      }
-    ],
+    "minProperties": 1,
     "properties": {
       "timeservers": {
         "type": "array",
@@ -90,6 +81,164 @@
       "leapsectz": {
         "type": "string",
         "description": "Timezone used by chronyd to determine when will the next leap second occur. Empty value will remove the option."
+      },
+      "refclocks": {
+        "type": "array",
+        "items": {
+          "type": "object",
+          "additionalProperties": false,
+          "required": [
+            "driver"
+          ],
+          "properties": {
+            "driver": {
+              "oneOf": [
+                {
+                  "$ref": "#/definitions/PPS"
+                },
+                {
+                  "$ref": "#/definitions/SHM"
+                },
+                {
+                  "$ref": "#/definitions/SOCK"
+                },
+                {
+                  "$ref": "#/definitions/PHC"
+                }
+              ]
+            },
+            "poll": {
+              "type": "integer",
+              "description": "Specifies the interval between processing times of timestamps as a power of 2 in seconds."
+            },
+            "dpoll": {
+              "type": "integer",
+              "description": "Some drivers do not listen for external events and try to produce samples in their own polling interval. This is defined as a power of 2 and can be negative to specify a sub-second interval. The default is 0 (1 second)."
+            },
+            "offset": {
+              "type": "number",
+              "description": "This option can be used to compensate for a constant error. The default is 0.0."
+            }
+          }
+        }
+      }
+    },
+    "definitions": {
+      "PPS": {
+        "description": "Driver for the kernel PPS (pulse per second) API.",
+        "type": "object",
+        "required": [
+          "name",
+          "device"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "name": {
+            "type": "string",
+            "enum": [
+              "PPS"
+            ]
+          },
+          "device": {
+            "type": "string",
+            "description": "Path to the PPS device (typically /dev/pps?).",
+            "pattern": "^\\/(?!\\.\\.)((?!\\/\\.\\.\\/).)+$"
+          },
+          "clear": {
+            "type": "boolean",
+            "description": "By default, the PPS refclock uses assert events (rising edge) for synchronisation. With this option, it will use clear events (falling edge) instead."
+          }
+        }
+      },
+      "SHM": {
+        "description": "NTP shared memory driver.",
+        "type": "object",
+        "required": [
+          "name",
+          "segment"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "name": {
+            "type": "string",
+            "enum": [
+              "SHM"
+            ]
+          },
+          "segment": {
+            "type": "integer",
+            "description": "The number of the shared memory segment."
+          },
+          "perm": {
+            "type": "string",
+            "pattern": "^[0-7]{4}$",
+            "description": "This option specifies the permissions of the shared memory segment created by chronyd. They are specified as a numeric mode. The default value is 0600 (read-write access for owner only)."
+          }
+        }
+      },
+      "SOCK": {
+        "description": "Unix domain socket driver.",
+        "type": "object",
+        "required": [
+          "name",
+          "path"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "name": {
+            "type": "string",
+            "enum": [
+              "SOCK"
+            ]
+          },
+          "path": {
+            "type": "string",
+            "pattern": "^\\/(?!\\.\\.)((?!\\/\\.\\.\\/).)+$",
+            "description": "The path to the socket."
+          }
+        }
+      },
+      "PHC": {
+        "description": "Unix domain socket driver.",
+        "type": "object",
+        "required": [
+          "name",
+          "path"
+        ],
+        "additionalProperties": false,
+        "properties": {
+          "name": {
+            "type": "string",
+            "enum": [
+              "PHC"
+            ]
+          },
+          "path": {
+            "type": "string",
+            "pattern": "^\\/(?!\\.\\.)((?!\\/\\.\\.\\/).)+$",
+            "description": "The path to the device of the PTP clock to be used as a time source."
+          },
+          "nocrossts": {
+            "type": "boolean",
+            "description": "Disable use of precise cross timestamping."
+          },
+          "extpps": {
+            "type": "boolean",
+            "description": "Enable a PPS mode in which the PTP clock is timestamping pulses of an external PPS signal connected to the clock."
+          },
+          "pin": {
+            "type": "integer",
+            "description": "The index of the pin for the PPS mode. The default value is 0."
+          },
+          "channel": {
+            "type": "integer",
+            "description": "The index of the channel for the PPS mode. The default value is 0."
+          },
+          "clear": {
+            "type": "boolean",
+            "description": "This option enables timestamping of clear events (falling edge) instead of assert events (rising edge) in the PPS mode. This may not work with some clocks."
+          }
+        }
       }
     }
   }