diff --git a/pyproject.toml b/pyproject.toml
index 4eb3c0f8..037f7804 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,7 @@ classifiers = [
     "Programming Language :: Python :: 3 :: Only",
     "Programming Language :: Python :: 3.8",
     "Programming Language :: Python :: 3.9",
-    "Topic :: Scientific/Engineering : Mathematics",
+    "Topic :: Scientific/Engineering :: Mathematics",
 ]
 dependencies = [
     "numpy >= 1.15.0",