diff --git a/src/pg/sql/04_py_agg.sql b/src/pg/sql/04_py_agg.sql
index c38e323..a3e881b 100644
--- a/src/pg/sql/04_py_agg.sql
+++ b/src/pg/sql/04_py_agg.sql
@@ -10,10 +10,22 @@ CREATE OR REPLACE FUNCTION
     END
     $$ LANGUAGE plpgsql;
 
-
-CREATE AGGREGATE CDB_PyAgg(NUMERIC[])(
-    SFUNC = CDB_PyAggS,
-    STYPE = Numeric[],
-    INITCOND = "{}" 
-);
-
+-- Create aggregate if it did not exist
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT *
+        FROM pg_catalog.pg_proc p
+            LEFT JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
+        WHERE n.nspname = 'cdb_crankshaft'
+            AND p.proname = 'cdb_pyagg'
+            AND p.proisagg)
+    THEN
+        CREATE AGGREGATE CDB_PyAgg(NUMERIC[]) (
+            SFUNC = CDB_PyAggS,
+            STYPE = Numeric[],
+            INITCOND = "{}"
+        );
+    END IF;
+END
+$$ LANGUAGE plpgsql;
diff --git a/src/pg/sql/11_kmeans.sql b/src/pg/sql/11_kmeans.sql
index 125aac3..f20942f 100644
--- a/src/pg/sql/11_kmeans.sql
+++ b/src/pg/sql/11_kmeans.sql
@@ -41,9 +41,23 @@ BEGIN
 END
 $$ LANGUAGE plpgsql;
 
-CREATE AGGREGATE CDB_WeightedMean(geometry(Point, 4326), NUMERIC)(
-    SFUNC = CDB_WeightedMeanS,
-    FINALFUNC = CDB_WeightedMeanF,
-    STYPE = Numeric[],
-    INITCOND = "{0.0,0.0,0.0}" 
-);
+-- Create aggregate if it did not exist
+DO $$
+BEGIN
+    IF NOT EXISTS (
+        SELECT *
+        FROM pg_catalog.pg_proc p
+            LEFT JOIN pg_catalog.pg_namespace n ON n.oid = p.pronamespace
+        WHERE n.nspname = 'cdb_crankshaft'
+            AND p.proname = 'cdb_weightedmean'
+            AND p.proisagg)
+    THEN
+        CREATE AGGREGATE CDB_WeightedMean(geometry(Point, 4326), NUMERIC) (
+            SFUNC = CDB_WeightedMeanS,
+            FINALFUNC = CDB_WeightedMeanF,
+            STYPE = Numeric[],
+            INITCOND = "{0.0,0.0,0.0}" 
+        );
+    END IF;
+END
+$$ LANGUAGE plpgsql;