diff --git a/.github/workflows/test-and-build.yml b/.github/workflows/test-and-build.yml
index 1317244..ea6d6c1 100644
--- a/.github/workflows/test-and-build.yml
+++ b/.github/workflows/test-and-build.yml
@@ -34,19 +34,32 @@ jobs:
     strategy:
       matrix:
         go-version:
-          - '1.18' # oldest supported; named in go.mod
+          - '1.23' # named in go.mod
           - 'oldstable'
           - 'stable'
     env:
       TEST_RESULTS: "/tmp/test-results"
     steps:
-      - uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
-      - uses: actions/setup-go@f111f3307d8850f501ac008e886eec1fd1932a34 # v5.3.0
+      - name: Checkout Code
+        uses: actions/checkout@44c2b7a8a4ea60a981eaca3cf939b5f4305c123b # v4.1.5
+      - name: Setup go
+        uses: actions/setup-go@f111f3307d8850f501ac008e886eec1fd1932a34 # v5.3.0
         with:
           go-version: ${{ matrix.go-version }}
           cache: true
+      - name: Run golangci-lint
+        uses: golangci/golangci-lint-action@08e2f20817b15149a52b5b3ebe7de50aff2ba8c5
       - uses: autero1/action-gotestsum@7263b9d73912eec65f46337689e59fac865c425f # v2.0.0
         with:
           gotestsum_version: 1.9.0
-
-      - run: make test
+      - name: Run test
+        run: make test
+      - name: Unit test coverage
+        run: make coverage
+      - name: Upload coverage report
+        uses: actions/upload-artifact@65462800fd760344b1a7b4382951275a0abb4808
+        with:
+          path: /tmp/coverage.out
+          name: Coverage-report-${{ matrix.go-version }}
+      - name: Display coverage report
+        run: go tool cover -func=/tmp/coverage.out
\ No newline at end of file
diff --git a/.go-version b/.go-version
new file mode 100644
index 0000000..193d140
--- /dev/null
+++ b/.go-version
@@ -0,0 +1 @@
+1.23
\ No newline at end of file
diff --git a/.golangci.yml b/.golangci.yml
new file mode 100644
index 0000000..8467b99
--- /dev/null
+++ b/.golangci.yml
@@ -0,0 +1,4 @@
+linters:
+ enable:
+   - errcheck
+output_format: colored-line-number
\ No newline at end of file
diff --git a/common_test.go b/common_test.go
index 00fbc0c..58079bd 100644
--- a/common_test.go
+++ b/common_test.go
@@ -5,7 +5,6 @@ package bexpr
 
 import (
 	"flag"
-	"reflect"
 )
 
 var benchFull *bool = flag.Bool("bench-full", false, "Run all benchmarks rather than a subset")
@@ -71,23 +70,6 @@ type testFlatStructAlt struct {
 	Hidden     CustomBool `bexpr:"-"`
 }
 
-var testFlatStructKindMap map[string]reflect.Kind = map[string]reflect.Kind{
-	"Int":     reflect.Int,
-	"Int8":    reflect.Int8,
-	"Int16":   reflect.Int16,
-	"Int32":   reflect.Int32,
-	"Int64":   reflect.Int64,
-	"Uint":    reflect.Uint,
-	"Uint8":   reflect.Uint8,
-	"Uint16":  reflect.Uint16,
-	"Uint32":  reflect.Uint32,
-	"Uint64":  reflect.Uint64,
-	"Float32": reflect.Float32,
-	"Float64": reflect.Float64,
-	"Bool":    reflect.Bool,
-	"String":  reflect.String,
-}
-
 type testNestedLevel2_1 struct {
 	Foo int
 	bar string
diff --git a/evaluate_test.go b/evaluate_test.go
index 138ad38..1d52ab3 100644
--- a/evaluate_test.go
+++ b/evaluate_test.go
@@ -124,21 +124,22 @@ var evaluateTests map[string]expressionTest = map[string]expressionTest{
 	},
 	"Flat Struct Alt Types": {
 		testFlatStructAlt{
-			Int:     -1,
-			Int8:    -2,
-			Int16:   -3,
-			Int32:   -4,
-			Int64:   -5,
-			Uint:    6,
-			Uint8:   7,
-			Uint16:  8,
-			Uint32:  9,
-			Uint64:  10,
-			Float32: 1.1,
-			Float64: 1.2,
-			Bool:    true,
-			String:  "exported",
-			Hidden:  true,
+			Int:        -1,
+			Int8:       -2,
+			Int16:      -3,
+			Int32:      -4,
+			Int64:      -5,
+			Uint:       6,
+			Uint8:      7,
+			Uint16:     8,
+			Uint32:     9,
+			Uint64:     10,
+			Float32:    1.1,
+			Float64:    1.2,
+			Bool:       true,
+			String:     "exported",
+			unexported: "unexported",
+			Hidden:     true,
 		},
 		[]expressionCheck{
 			{expression: "Int == -1", result: true, benchQuick: true},
@@ -255,10 +256,12 @@ var evaluateTests map[string]expressionTest = map[string]expressionTest{
 				MapOfStructs: map[string]testNestedLevel2_1{
 					"one": {
 						Foo: 42,
+						bar: "unexported",
 						Baz: "exported",
 					},
 					"two": {
 						Foo: 77,
+						bar: "unexported",
 						Baz: "consul",
 					},
 				},
@@ -300,6 +303,11 @@ var evaluateTests map[string]expressionTest = map[string]expressionTest{
 			{expression: "TopInt != 0", result: true},
 			{expression: "Nested.Map contains nope or (Nested.Map contains bar and Nested.Map.bar == `bazel`) or TopInt != 0", result: true, benchQuick: true},
 			{expression: "Nested.MapOfStructs.one.Foo == 42", result: true},
+			{expression: "Nested.MapOfStructs.one.bar == `unexported`", result: false, err: `error finding value in datum: /Nested/MapOfStructs/one/bar at part 3: couldn't find key: struct field with name "bar"`},
+			{expression: "Nested.MapOfStructs.one.Baz == `exported`", result: true},
+			{expression: "Nested.MapOfStructs.two.Foo == 77", result: true},
+			{expression: "Nested.MapOfStructs.two.bar == `unexported`", result: false, err: `error finding value in datum: /Nested/MapOfStructs/two/bar at part 3: couldn't find key: struct field with name "bar"`},
+			{expression: "Nested.MapOfStructs.two.Baz == `consul`", result: true},
 			{expression: "7 in Nested.SliceOfInts", result: true},
 			{expression: `"/Nested/SliceOfInts" == "7"`, result: false, err: `unable to find suitable primitive comparison function for matching`},
 			{expression: "Nested.MapOfStructs is empty or (Nested.SliceOfInts contains 7 and 9 in Nested.SliceOfInts)", result: true, benchQuick: true},
diff --git a/go.mod b/go.mod
index fed408d..46e827a 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/hashicorp/go-bexpr
 
-go 1.18
+go 1.23
 
 require (
 	github.com/mitchellh/pointerstructure v1.2.1