diff --git a/Project.toml b/Project.toml
index ecdc3319..e7abad4c 100644
--- a/Project.toml
+++ b/Project.toml
@@ -35,7 +35,7 @@ DocStringExtensions = "0.9"
 Documenter = "1"
 DocumenterCitations = "1"
 FFTW = "1.9.0"
-JSON = "0.21"
+JSON = "0.21, 1"
 MCMCChains = "6, 7"
 MCMCDiagnosticTools = "0.3"
 MPIPreferences = "0.1"