diff --git a/partiql-ast/src/test/kotlin/org/partiql/ast/normalize/NormalizeTest.kt b/partiql-ast/src/test/kotlin/org/partiql/ast/normalize/NormalizeTest.kt
index a2c7e86db3..566e3669ee 100644
--- a/partiql-ast/src/test/kotlin/org/partiql/ast/normalize/NormalizeTest.kt
+++ b/partiql-ast/src/test/kotlin/org/partiql/ast/normalize/NormalizeTest.kt
@@ -7,4 +7,4 @@ class NormalizeTest {
     @Test
     fun normalize() {
     }
-}
\ No newline at end of file
+}
diff --git a/partiql-planner/src/main/kotlin/org/partiql/planner/typer/PlanTyper.kt b/partiql-planner/src/main/kotlin/org/partiql/planner/typer/PlanTyper.kt
index 4651006757..369dcf5474 100644
--- a/partiql-planner/src/main/kotlin/org/partiql/planner/typer/PlanTyper.kt
+++ b/partiql-planner/src/main/kotlin/org/partiql/planner/typer/PlanTyper.kt
@@ -811,7 +811,13 @@ internal class PlanTyper(
                     // Found a match!
                     val newAgg = aggResolved(match.signature)
                     val newArgs = rewriteFnArgs(match.mapping, args)
-                    var type = newAgg.signature.returns.toStaticType()
+                    val returns = newAgg.signature.returns
+
+                    // Return type with calculated nullability
+                    var type = when {
+                        newAgg.signature.isNullable -> returns.toStaticType()
+                        else -> returns.toNonNullStaticType()
+                    }
 
                     // Some operators can return MISSING during runtime
                     if (match.isMissable) {
diff --git a/partiql-planner/src/testFixtures/resources/tests/aggregations.ion b/partiql-planner/src/testFixtures/resources/tests/aggregations.ion
index 718578921d..2badeb8dd6 100644
--- a/partiql-planner/src/testFixtures/resources/tests/aggregations.ion
+++ b/partiql-planner/src/testFixtures/resources/tests/aggregations.ion
@@ -116,7 +116,10 @@ suite::{
           fields: [
             {
               name: "avg",
-              type: "int32"
+              type: [
+                "int32",
+                "null"
+              ],
             },
           ],
         },
@@ -150,7 +153,10 @@ suite::{
           fields: [
             {
               name: "min",
-              type: "int32"
+              type: [
+                "int32",
+                "null"
+              ],
             },
           ],
         },
@@ -167,7 +173,10 @@ suite::{
           fields: [
             {
               name: "max",
-              type: "int32"
+              type: [
+                "int32",
+                "null"
+              ],
             },
           ],
         },
@@ -184,7 +193,10 @@ suite::{
           fields: [
             {
               name: "sum",
-              type: "int32"
+              type: [
+                "int32",
+                "null"
+              ],
             },
           ],
         },
@@ -224,7 +236,10 @@ suite::{
           fields: [
             {
               name: "_1",
-              type: "float32"
+              type: [
+                "float32",
+                "null"
+              ],
             },
             {
               name: "y",
@@ -250,7 +265,10 @@ suite::{
           fields: [
             {
               name: "_1",
-              type: "float32"
+              type: [
+                "float32",
+                "null"
+              ],
             },
             {
               name: "a",