diff --git a/.changeset/eventsource-upgrade.md b/.changeset/eventsource-upgrade.md
new file mode 100644
index 00000000..0fa81f18
--- /dev/null
+++ b/.changeset/eventsource-upgrade.md
@@ -0,0 +1,5 @@
+---
+'@sanity/client': minor
+---
+
+fix: abort underlying EventSource request when response fails validation
diff --git a/package.json b/package.json
index a1c7e77a..a2054e3a 100644
--- a/package.json
+++ b/package.json
@@ -110,7 +110,7 @@
     "generate:context": "node scripts/prune-context-spec.mjs src/context/openapi.json .tmp/context-openapi.pruned.json && pnpm --package=typescript@5.9.3 --package=openapi-typescript@7.13.0 dlx openapi-typescript .tmp/context-openapi.pruned.json -o src/context/types.gen.ts && oxfmt src/context/openapi.json src/context/types.gen.ts"
   },
   "dependencies": {
-    "eventsource": "^5.1.1",
+    "eventsource": "^5.1.2",
     "get-it": "^9.5.4",
     "obug": "^3.0.0",
     "rxjs": "^7.8.2"
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index d0b3fbd5..dce3e62a 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -9,8 +9,8 @@ importers:
   .:
     dependencies:
       eventsource:
-        specifier: ^5.1.1
-        version: 5.1.1
+        specifier: ^5.1.2
+        version: 5.1.2
       get-it:
         specifier: ^9.5.4
         version: 9.5.4(vitest@4.1.11)
@@ -2824,12 +2824,12 @@ packages:
     resolution: {integrity: sha512-iG7mY5LhweLKpgxQ+YdW7Y6YjBgRzGMrKlXzeUpm0VtJpdeag32Q/DMQ11HAT7kO9Jx8dreUL5SHGl6KAGJ9Lg==}
     engines: {node: '>=18.0.0'}
 
-  eventsource-parser@4.1.0:
-    resolution: {integrity: sha512-+DHvQ1wLO//MK+1OZgcuXCbZFKgu3YjKPJt7n98rxX8vezL0ni+7s3ZQiM8bJkUEOk7MsuCycrPLj0FzUNf7Og==}
+  eventsource-parser@4.1.1:
+    resolution: {integrity: sha512-zaWNqeSLeyzEAAt2Q6aDBRDRk/VnPmsKqvToyGvv6aahvLv71A4Jw7jG93Hckf11zXurbqgsffvpSgKPoeU1Qw==}
     engines: {node: '>=22.12'}
 
-  eventsource@5.1.1:
-    resolution: {integrity: sha512-onrlI7l612Ee3xnBqZNTq4djf6Fho/0yIpO/rYjRG/FzjMyPJquNx9SS3QyjglnVFxwxrube1XmX41zB+0Rdgw==}
+  eventsource@5.1.2:
+    resolution: {integrity: sha512-VJnwqqp+fOT3WDkjnUy49Zuyh48+kH0JdJApZkslrRQyx35zIZJeJYJl0+a+LrTzh5TFv6MdmXnBDv71UXFyWQ==}
     engines: {node: '>=22.12.0'}
 
   expect-type@1.4.0:
@@ -6947,11 +6947,11 @@ snapshots:
 
   eventsource-encoder@1.0.2: {}
 
-  eventsource-parser@4.1.0: {}
+  eventsource-parser@4.1.1: {}
 
-  eventsource@5.1.1:
+  eventsource@5.1.2:
     dependencies:
-      eventsource-parser: 4.1.0
+      eventsource-parser: 4.1.1
 
   expect-type@1.4.0: {}
 
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 150f71da..01c8654d 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -21,3 +21,4 @@ allowBuilds:
 # reviewed and are allowed through.
 minimumReleaseAgeExclude:
   - get-it@9.5.2 || 9.5.4
+  - eventsource@5.1.2