diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7a0027724c..527764e4a6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -26,6 +26,8 @@ release.
   ([#297](https://github.com/open-telemetry/semantic-conventions/pull/297))
 - Fix `server.port` to be not required when `server.address` is not set.
   ([#429](https://github.com/open-telemetry/semantic-conventions/pull/429))
+- Use seconds as default duration for FaaS duration histograms
+  ([#384](https://github.com/open-telemetry/semantic-conventions/pull/384))
 
 ### Features
 
diff --git a/docs/faas/faas-metrics.md b/docs/faas/faas-metrics.md
index b64d90dd01..e84a0921dc 100644
--- a/docs/faas/faas-metrics.md
+++ b/docs/faas/faas-metrics.md
@@ -45,10 +45,14 @@ The following metrics are recorded by the FaaS instance.
 
 This metric is [recommended][MetricRecommended].
 
+This metric SHOULD be specified with
+[`ExplicitBucketBoundaries`](https://github.com/open-telemetry/opentelemetry-specification/tree/v1.26.0/specification/metrics/api.md#instrument-advice)
+of `[ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ]`.
+
 <!-- semconv metric.faas.invoke_duration(metric_table) -->
 | Name     | Instrument Type | Unit (UCUM) | Description    |
 | -------- | --------------- | ----------- | -------------- |
-| `faas.invoke_duration` | Histogram | `ms` | Measures the duration of the function's logic execution |
+| `faas.invoke_duration` | Histogram | `s` | Measures the duration of the function's logic execution |
 <!-- endsemconv -->
 
 <!-- semconv metric.faas.invoke_duration(full) -->
@@ -71,10 +75,14 @@ This metric is [recommended][MetricRecommended].
 
 This metric is [recommended][MetricRecommended].
 
+This metric SHOULD be specified with
+[`ExplicitBucketBoundaries`](https://github.com/open-telemetry/opentelemetry-specification/tree/v1.26.0/specification/metrics/api.md#instrument-advice)
+of `[ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ]`.
+
 <!-- semconv metric.faas.init_duration(metric_table) -->
 | Name     | Instrument Type | Unit (UCUM) | Description    |
 | -------- | --------------- | ----------- | -------------- |
-| `faas.init_duration` | Histogram | `ms` | Measures the duration of the function's initialization, such as a cold start |
+| `faas.init_duration` | Histogram | `s` | Measures the duration of the function's initialization, such as a cold start |
 <!-- endsemconv -->
 
 <!-- semconv metric.faas.init_duration(full) -->
@@ -227,10 +235,14 @@ This metric is [recommended][MetricRecommended].
 
 This metric is [recommended][MetricRecommended].
 
+This metric SHOULD be specified with
+[`ExplicitBucketBoundaries`](https://github.com/open-telemetry/opentelemetry-specification/tree/v1.26.0/specification/metrics/api.md#instrument-advice)
+of `[ 0.005, 0.01, 0.025, 0.05, 0.075, 0.1, 0.25, 0.5, 0.75, 1, 2.5, 5, 7.5, 10 ]`.
+
 <!-- semconv metric.faas.cpu_usage(metric_table) -->
 | Name     | Instrument Type | Unit (UCUM) | Description    |
 | -------- | --------------- | ----------- | -------------- |
-| `faas.cpu_usage` | Histogram | `ms` | Distribution of CPU usage per invocation |
+| `faas.cpu_usage` | Histogram | `s` | Distribution of CPU usage per invocation |
 <!-- endsemconv -->
 
 <!-- semconv metric.faas.cpu_usage(full) -->
diff --git a/model/metrics/faas-metrics.yaml b/model/metrics/faas-metrics.yaml
index 6a753a7351..d68119f320 100644
--- a/model/metrics/faas-metrics.yaml
+++ b/model/metrics/faas-metrics.yaml
@@ -4,7 +4,7 @@ groups:
     metric_name: faas.invoke_duration
     brief: "Measures the duration of the function's logic execution"
     instrument: histogram
-    unit: "ms"
+    unit: "s"
     attributes:
       - ref: faas.trigger
 
@@ -13,7 +13,7 @@ groups:
     metric_name: faas.init_duration
     brief: "Measures the duration of the function's initialization, such as a cold start"
     instrument: histogram
-    unit: "ms"
+    unit: "s"
     attributes:
       - ref: faas.trigger
 
@@ -67,7 +67,7 @@ groups:
     metric_name: faas.cpu_usage
     brief: "Distribution of CPU usage per invocation"
     instrument: histogram
-    unit: "ms"
+    unit: "s"
     attributes:
       - ref: faas.trigger