diff --git a/src/main/jwt_full/claims.nim b/src/main/jwt_full/claims.nim
index f08bf5a..25228db 100644
--- a/src/main/jwt_full/claims.nim
+++ b/src/main/jwt_full/claims.nim
@@ -59,7 +59,7 @@ proc initJwtClaims*(n: JsonNode): JwtClaims =
   ## Create a JwtClaims from a given set of claims as a JsonNOde
 
   return JwtClaims(
-    rawB64: $n,
+    rawB64: b64UrlEncode($n),
     json: n,
     iss: n.optStrVal("iss"),
     sub: n.optStrVal("sub"),
diff --git a/src/test/unit/tclaims.nim b/src/test/unit/tclaims.nim
index dcbb156..ef381e3 100644
--- a/src/test/unit/tclaims.nim
+++ b/src/test/unit/tclaims.nim
@@ -22,6 +22,17 @@ suite "jwt_full/claims":
       sampleClaims["name"].isSome
       sampleClaims["name"].get.getStr == "John Doe"
 
+  test "initClaims(json)":
+    let jsonClaims = initJwtClaims(parseJson(sampleJwtClaimsDecoded))
+
+    check:
+      jsonClaims.sub.isSome
+      jsonClaims.sub.get == "abc"
+      jsonClaims["name"].isSome
+      jsonClaims["name"].get.getStr == "John Doe"
+      jsonClaims.iss.isNone
+      $jsonClaims == "eyJzdWIiOiJhYmMiLCJuYW1lIjoiSm9obiBEb2UiLCJpYXQiOjE1MTYyMzkwMjJ9"
+
   test "round trip":
     let rfcClaims1 = initJwtClaims(rfc7519_S31_ClaimsB64)
     let rfcClaims2 = initJwtClaims($rfcClaims1)
diff --git a/src/test/unit/tjws.nim b/src/test/unit/tjws.nim
index 5d5fb30..72e9fed 100644
--- a/src/test/unit/tjws.nim
+++ b/src/test/unit/tjws.nim
@@ -24,7 +24,7 @@ suite "jwt_full/jws":
 
     check sampleJwt == $sign(
       header = initJoseHeader(parseJson(sampleJwtHeaderDecoded)),
-      payload = $initJwtClaims(parseJson(sampleJwtClaimsDecoded)),
+      payload = sampleJwtClaimsDecoded,
       key = initJwk(parseJson(sampleJwtKey)))
 
   test "HS256 - verify":