diff --git a/crates/claims/crates/data-integrity/core/src/lib.rs b/crates/claims/crates/data-integrity/core/src/lib.rs
index 24a8853df..2d5a1b065 100644
--- a/crates/claims/crates/data-integrity/core/src/lib.rs
+++ b/crates/claims/crates/data-integrity/core/src/lib.rs
@@ -16,6 +16,7 @@ pub mod suite;
 pub use decode::*;
 use educe::Educe;
 pub use options::ProofOptions;
+pub use proof::value_or_array;
 pub use proof::*;
 use serde::Serialize;
 use ssi_claims_core::{
diff --git a/crates/claims/crates/data-integrity/core/src/options.rs b/crates/claims/crates/data-integrity/core/src/options.rs
index 0ed4e670e..791063bca 100644
--- a/crates/claims/crates/data-integrity/core/src/options.rs
+++ b/crates/claims/crates/data-integrity/core/src/options.rs
@@ -40,7 +40,12 @@ pub struct ProofOptions<M, T> {
     /// Example domain values include: `domain.example`` (DNS domain),
     /// `https://domain.example:8443` (Web origin), `mycorp-intranet` (bespoke
     /// text string), and `b31d37d4-dd59-47d3-9dd8-c973da43b63a` (UUID).
-    #[serde(default, skip_serializing_if = "Vec::is_empty", rename = "domain")]
+    #[serde(
+        default,
+        with = "crate::value_or_array",
+        skip_serializing_if = "Vec::is_empty",
+        rename = "domain"
+    )]
     pub domains: Vec<String>,
 
     /// Used to mitigate replay attacks.
diff --git a/crates/claims/crates/data-integrity/core/src/proof/configuration/mod.rs b/crates/claims/crates/data-integrity/core/src/proof/configuration/mod.rs
index 0e6fe7146..5e6d1e471 100644
--- a/crates/claims/crates/data-integrity/core/src/proof/configuration/mod.rs
+++ b/crates/claims/crates/data-integrity/core/src/proof/configuration/mod.rs
@@ -57,7 +57,11 @@ pub struct ProofConfiguration<S: CryptographicSuite> {
     /// Example domain values include: `domain.example`` (DNS domain),
     /// `https://domain.example:8443` (Web origin), `mycorp-intranet` (bespoke
     /// text string), and `b31d37d4-dd59-47d3-9dd8-c973da43b63a` (UUID).
-    #[serde(skip_serializing_if = "Vec::is_empty", rename = "domain")]
+    #[serde(
+        with = "crate::value_or_array",
+        skip_serializing_if = "Vec::is_empty",
+        rename = "domain"
+    )]
     pub domains: Vec<String>,
 
     /// Used to mitigate replay attacks.
diff --git a/crates/claims/crates/data-integrity/core/src/proof/configuration/reference.rs b/crates/claims/crates/data-integrity/core/src/proof/configuration/reference.rs
index 30668a2a6..20b700163 100644
--- a/crates/claims/crates/data-integrity/core/src/proof/configuration/reference.rs
+++ b/crates/claims/crates/data-integrity/core/src/proof/configuration/reference.rs
@@ -30,7 +30,11 @@ pub struct ProofConfigurationRef<'a, S: CryptographicSuite> {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub expires: Option<xsd_types::DateTimeStamp>,
 
-    #[serde(skip_serializing_if = "<[String]>::is_empty")]
+    #[serde(
+        with = "crate::value_or_array",
+        skip_serializing_if = "<[String]>::is_empty",
+        rename = "domain"
+    )]
     pub domains: &'a [String],
 
     #[serde(skip_serializing_if = "Option::is_none")]
@@ -151,7 +155,11 @@ pub struct ProofConfigurationRefWithoutOptions<'a, S: CryptographicSuite> {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub expires: Option<xsd_types::DateTimeStamp>,
 
-    #[serde(skip_serializing_if = "<[String]>::is_empty")]
+    #[serde(
+        with = "crate::value_or_array",
+        skip_serializing_if = "<[String]>::is_empty",
+        rename = "domain"
+    )]
     pub domains: &'a [String],
 
     #[serde(skip_serializing_if = "Option::is_none")]
diff --git a/crates/claims/crates/data-integrity/core/src/proof/mod.rs b/crates/claims/crates/data-integrity/core/src/proof/mod.rs
index 16c138d9c..660462792 100644
--- a/crates/claims/crates/data-integrity/core/src/proof/mod.rs
+++ b/crates/claims/crates/data-integrity/core/src/proof/mod.rs
@@ -81,7 +81,11 @@ pub struct Proof<S: CryptographicSuite> {
     /// Example domain values include: `domain.example`` (DNS domain),
     /// `https://domain.example:8443` (Web origin), `mycorp-intranet` (bespoke
     /// text string), and `b31d37d4-dd59-47d3-9dd8-c973da43b63a` (UUID).
-    #[serde(skip_serializing_if = "Vec::is_empty", rename = "domain")]
+    #[serde(
+        with = "crate::value_or_array",
+        skip_serializing_if = "Vec::is_empty",
+        rename = "domain"
+    )]
     pub domains: Vec<String>,
 
     /// Used to mitigate replay attacks.
@@ -441,3 +445,25 @@ impl<'de, S: DeserializeCryptographicSuite<'de>> Deserialize<'de> for Proofs<S>
         }
     }
 }
+
+pub mod value_or_array {
+    use serde::{Deserialize, Serialize};
+    use ssi_core::OneOrMany;
+
+    pub fn serialize<T: Serialize, S>(value: &[T], serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        match value.split_first() {
+            Some((first, [])) => first.serialize(serializer),
+            _ => value.serialize(serializer),
+        }
+    }
+
+    pub fn deserialize<'de, T: Deserialize<'de>, D>(deserializer: D) -> Result<Vec<T>, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Ok(OneOrMany::deserialize(deserializer)?.into_vec())
+    }
+}