diff --git a/pyproject.toml b/pyproject.toml
index 5251871..24d0f1b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,7 +44,7 @@ test = [
     "flake8>=3.9.2",
     "flake8-docstrings>=1.6.0",
     "pytest-cov>=2.12.0",
-    "pytest-regtest>=1.5.1"
+    "pytest-regtest>=1.5.1,<2"
 ]
 dev = [
     "tox>=3.20.1",