diff --git a/source/client-side-encryption/client-side-encryption.md b/source/client-side-encryption/client-side-encryption.md
index b683908608..930c18098b 100644
--- a/source/client-side-encryption/client-side-encryption.md
+++ b/source/client-side-encryption/client-side-encryption.md
@@ -376,7 +376,7 @@ class AutoEncryptionOpts {
    // Set bypassQueryAnalysis to true to use explicit encryption on indexed fields
    // without the MongoDB Enterprise Advanced licensed crypt_shared library.
    bypassQueryAnalysis: Optional<Boolean>; // Default false.
-   keyExpirationMS: Optional<Uint64>; // Default 60000.
+   keyExpirationMS: Optional<Uint64>; // Default 60000. 0 means "never expire".
 }
 ```
 
@@ -1049,7 +1049,7 @@ interface ClientEncryptionOpts {
    keyVaultNamespace: String;
    kmsProviders: KMSProviders;
    tlsOptions?: KMSProvidersTLSOptions; // Maps KMS provider to TLS options.
-   keyExpirationMS: Optional<Uint64>; // Default 60000.
+   keyExpirationMS: Optional<Uint64>; // Default 60000. 0 means "never expire".
 };
 
 interface KMSProvidersTLSOptions {
diff --git a/source/client-side-encryption/etc/test-templates/keyCache.yml.template b/source/client-side-encryption/etc/test-templates/keyCache.yml.template
index 700057d73f..4842a0bab2 100644
--- a/source/client-side-encryption/etc/test-templates/keyCache.yml.template
+++ b/source/client-side-encryption/etc/test-templates/keyCache.yml.template
@@ -21,7 +21,7 @@ tests:
       - name: wait
         object: testRunner
         arguments:
-          ms: 2
+          ms: 50 # Wait long enough to account for coarse time resolution on Windows (CDRIVER-4526).
       - name: find
         arguments:
           filter: { _id: 1 }
@@ -66,4 +66,4 @@ tests:
       collection:
         # Outcome is checked using a separate MongoClient without auto encryption.
         data:
-          - *doc0_encrypted
\ No newline at end of file
+          - *doc0_encrypted
diff --git a/source/client-side-encryption/tests/legacy/keyCache.json b/source/client-side-encryption/tests/legacy/keyCache.json
index 49a6ca32bd..912ce80020 100644
--- a/source/client-side-encryption/tests/legacy/keyCache.json
+++ b/source/client-side-encryption/tests/legacy/keyCache.json
@@ -122,7 +122,7 @@
           "name": "wait",
           "object": "testRunner",
           "arguments": {
-            "ms": 2
+            "ms": 50
           }
         },
         {
diff --git a/source/client-side-encryption/tests/legacy/keyCache.yml b/source/client-side-encryption/tests/legacy/keyCache.yml
index ea3ebdc578..3af117ca81 100644
--- a/source/client-side-encryption/tests/legacy/keyCache.yml
+++ b/source/client-side-encryption/tests/legacy/keyCache.yml
@@ -21,7 +21,7 @@ tests:
       - name: wait
         object: testRunner
         arguments:
-          ms: 2
+          ms: 50 # Wait long enough to account for coarse time resolution on Windows (CDRIVER-4526).
       - name: find
         arguments:
           filter: { _id: 1 }
diff --git a/source/client-side-encryption/tests/unified/keyCache.json b/source/client-side-encryption/tests/unified/keyCache.json
index 36d5957a83..a39701e286 100644
--- a/source/client-side-encryption/tests/unified/keyCache.json
+++ b/source/client-side-encryption/tests/unified/keyCache.json
@@ -105,7 +105,7 @@
           "name": "wait",
           "object": "testRunner",
           "arguments": {
-            "ms": 2
+            "ms": 50
           }
         },
         {
diff --git a/source/client-side-encryption/tests/unified/keyCache.yml b/source/client-side-encryption/tests/unified/keyCache.yml
index 78aedda6a6..d6e747ba09 100644
--- a/source/client-side-encryption/tests/unified/keyCache.yml
+++ b/source/client-side-encryption/tests/unified/keyCache.yml
@@ -62,7 +62,7 @@ tests:
       - name: wait
         object: testRunner
         arguments:
-          ms: 2
+          ms: 50 # Wait long enough to account for coarse time resolution on Windows (CDRIVER-4526).
       - name: decrypt
         object: *clientEncryption0
         arguments:
@@ -82,4 +82,4 @@ tests:
                 find: datakeys
                 filter: {"$or": [{"_id": {"$in": [ {'$binary': {'base64': 'a+YWzdygTAG62/cNUkqZiQ==', 'subType': '04'}} ] }}, {"keyAltNames": {"$in": []}}]}
                 $db: keyvault
-                readConcern: { level: "majority" }
\ No newline at end of file
+                readConcern: { level: "majority" }