diff --git a/Project.toml b/Project.toml
index 8b58c3af20..1f79256b4f 100644
--- a/Project.toml
+++ b/Project.toml
@@ -20,7 +20,7 @@ BenchmarkTools = "0.4, 0.5"
 CodecBzip2 = "~0.6, 0.7"
 CodecZlib = "~0.6, 0.7"
 JSON = "~0.21"
-JSONSchema = "0.2"
+JSONSchema = "0.3"
 MutableArithmetics = "0.2"
 OrderedCollections = "1"
 julia = "1"
diff --git a/src/FileFormats/MOF/MOF.jl b/src/FileFormats/MOF/MOF.jl
index 02f6325d60..63028c1d7e 100644
--- a/src/FileFormats/MOF/MOF.jl
+++ b/src/FileFormats/MOF/MOF.jl
@@ -105,9 +105,12 @@ function validate(io::IO)
     object = JSON.parse(io)
     seekstart(io)
     mof_schema = JSONSchema.Schema(JSON.parsefile(SCHEMA_PATH, use_mmap=false))
-    if !JSONSchema.isvalid(object, mof_schema)
-        error("Unable to read file because it does not conform to the MOF " *
-              "schema: ", JSONSchema.diagnose(object, mof_schema))
+    ret = JSONSchema.validate(object, mof_schema)
+    if ret !== nothing
+        error(
+            "Unable to read file because it does not conform to the MOF " *
+            "schema: ", ret
+        )
     end
     return
 end