diff --git a/pyproject.toml b/pyproject.toml
index 4cb3a3027026521970892353cb132ba1fbd7534d..5dd83f83ae8105f5cb53765dac2c14504dbe5c88 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -38,6 +38,7 @@ dependencies = [
     "numpy",
     "pyopencl>=2022.1",
     "pytools>=2022.1",
+    "sympy>=0.7.2",
 ]
 
 [project.optional-dependencies]
@@ -49,9 +50,6 @@ doc = [
 fmmlib = [
     "pyfmmlib>=2023.1",
 ]
-sympy = [
-    "sympy>=0.7.2",
-]
 symengine = [
     "symengine>=0.9.0",
 ]