diff --git a/src/JSON.jl b/src/JSON.jl
index 2b424d0..3cb784d 100644
--- a/src/JSON.jl
+++ b/src/JSON.jl
@@ -87,8 +87,13 @@ function isvalidjson end
 
 isvalidjson(io::Union{IO, Base.AbstractCmd}; kw...) = isvalidjson(Base.read(io); kw...)
 
-isvalidjson(buf::Union{AbstractVector{UInt8}, AbstractString}; kw...) =
-    isvalidjson(lazy(buf; kw...))
+function isvalidjson(buf::Union{AbstractVector{UInt8}, AbstractString}; kw...)
+    try
+        return isvalidjson(lazy(buf; kw...))
+    catch
+        return false
+    end
+end
 
 function isvalidjson(x::LazyValue)
     try
diff --git a/test/parse.jl b/test/parse.jl
index 1a71312..c4d065e 100644
--- a/test/parse.jl
+++ b/test/parse.jl
@@ -282,6 +282,9 @@ end
         @test JSON.isvalidjson(io)
     end
     @test JSON.isvalidjson("{}")
+    @test !JSON.isvalidjson("{JSON")
+    @test !JSON.isvalidjson("JSON")
+    @test !JSON.isvalidjson(collect(codeunits("JSON")))
     x = JSON.parse("{}")
     @test isempty(x) && typeof(x) == JSON.Object{String, Any}
     @test_throws ArgumentError JSON.parse(JSON.LazyValue(".", 1, JSON.JSONTypes.OBJECT, JSON.LazyOptions(), true))