diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a62bb01..a81c216 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -82,7 +82,19 @@ jobs:
 
       - uses: actions/setup-go@v5
         with:
-          go-version: "1.23"
+          # gofmt is a standalone binary and does not follow the toolchain
+          # switch that go.mod's `go 1.25.0` triggers for go commands, so this
+          # job pins the version the module requires.
+          go-version: "1.25"
+
+      - name: Format check
+        run: |
+          unformatted=$(gofmt -l .)
+          if [ -n "$unformatted" ]; then
+            echo "gofmt -w . is needed for:"
+            echo "$unformatted"
+            exit 1
+          fi
 
       - name: Vet
         run: go vet ./...
diff --git a/internal/cli/download_cmd.go b/internal/cli/download_cmd.go
index 3617607..1ec4516 100644
--- a/internal/cli/download_cmd.go
+++ b/internal/cli/download_cmd.go
@@ -14,14 +14,14 @@ import (
 
 func newDownloadCmd() *cobra.Command {
 	var (
-		fromFile  string
-		urlsFile  string
-		singleURL string
-		outputDir string
-		parallel  int
+		fromFile   string
+		urlsFile   string
+		singleURL  string
+		outputDir  string
+		parallel   int
 		maxSamples int
-		dryRun    bool
-		force     bool
+		dryRun     bool
+		force      bool
 	)
 
 	cmd := &cobra.Command{
diff --git a/internal/cli/query_cmd.go b/internal/cli/query_cmd.go
index c16b099..120b371 100644
--- a/internal/cli/query_cmd.go
+++ b/internal/cli/query_cmd.go
@@ -14,8 +14,8 @@ import (
 
 	cols "github.com/allthebacteria/atb-cli/internal/columns"
 	idx "github.com/allthebacteria/atb-cli/internal/index"
-	pq "github.com/allthebacteria/atb-cli/internal/parquet"
 	"github.com/allthebacteria/atb-cli/internal/output"
+	pq "github.com/allthebacteria/atb-cli/internal/parquet"
 	"github.com/allthebacteria/atb-cli/internal/query"
 	"github.com/allthebacteria/atb-cli/internal/suggest"
 )
diff --git a/internal/index/query.go b/internal/index/query.go
index 4ac8259..5535cb8 100644
--- a/internal/index/query.go
+++ b/internal/index/query.go
@@ -72,40 +72,40 @@ type QueryParams struct {
 
 // userColToSQL maps user-facing column names to SQLite column names.
 var userColToSQL = map[string]string{
-	"sample_accession":    "sample_accession",
-	"run_accession":       "run_accession",
-	"assembly_accession":  "assembly_accession",
-	"sylph_species":       "sylph_species",
-	"hq_filter":           "hq_filter",
-	"asm_fasta_on_osf":    "asm_fasta_on_osf",
-	"dataset":             "dataset",
-	"scientific_name":     "scientific_name",
-	"aws_url":             "aws_url",
-	"osf_tarball_url":     "osf_tarball_url",
-	"total_length":        "total_length",
-	"number":              "num_contigs",
-	"N50":                 "n50",
-	"N90":                 "n90",
+	"sample_accession":     "sample_accession",
+	"run_accession":        "run_accession",
+	"assembly_accession":   "assembly_accession",
+	"sylph_species":        "sylph_species",
+	"hq_filter":            "hq_filter",
+	"asm_fasta_on_osf":     "asm_fasta_on_osf",
+	"dataset":              "dataset",
+	"scientific_name":      "scientific_name",
+	"aws_url":              "aws_url",
+	"osf_tarball_url":      "osf_tarball_url",
+	"total_length":         "total_length",
+	"number":               "num_contigs",
+	"N50":                  "n50",
+	"N90":                  "n90",
 	"Completeness_General": "completeness",
-	"Contamination":       "contamination",
-	"Genome_Size":         "genome_size",
-	"GC_Content":          "gc_content",
-	"mlst_scheme":         "mlst_scheme",
-	"mlst_st":             "mlst_st",
-	"mlst_status":         "mlst_status",
-	"mlst_score":          "mlst_score",
-	"mlst_alleles":        "mlst_alleles",
+	"Contamination":        "contamination",
+	"Genome_Size":          "genome_size",
+	"GC_Content":           "gc_content",
+	"mlst_scheme":          "mlst_scheme",
+	"mlst_st":              "mlst_st",
+	"mlst_status":          "mlst_status",
+	"mlst_score":           "mlst_score",
+	"mlst_alleles":         "mlst_alleles",
 }
 
 // sqlToUserCol is the reverse mapping, used when building result maps.
 var sqlToUserCol = map[string]string{
-	"num_contigs":  "number",
-	"n50":          "N50",
-	"n90":          "N90",
-	"completeness": "Completeness_General",
+	"num_contigs":   "number",
+	"n50":           "N50",
+	"n90":           "N90",
+	"completeness":  "Completeness_General",
 	"contamination": "Contamination",
-	"genome_size":  "Genome_Size",
-	"gc_content":   "GC_Content",
+	"genome_size":   "Genome_Size",
+	"gc_content":    "GC_Content",
 }
 
 // allSQLCols is the full list of columns in SELECT order.
diff --git a/internal/query/executor_test.go b/internal/query/executor_test.go
index 703e699..821be2a 100644
--- a/internal/query/executor_test.go
+++ b/internal/query/executor_test.go
@@ -294,10 +294,10 @@ func TestParseCollectionDate(t *testing.T) {
 		return t
 	}
 	cases := []struct {
-		in         string
-		wantOK     bool
-		wantStart  time.Time
-		wantEnd    time.Time
+		in        string
+		wantOK    bool
+		wantStart time.Time
+		wantEnd   time.Time
 	}{
 		{"2020-05-15", true, d("2020-05-15"), d("2020-05-15")},
 		{"2020-05", true, d("2020-05-01"), d("2020-05-31")},
diff --git a/internal/selfupdate/selfupdate.go b/internal/selfupdate/selfupdate.go
index c63d066..20d9236 100644
--- a/internal/selfupdate/selfupdate.go
+++ b/internal/selfupdate/selfupdate.go
@@ -14,9 +14,9 @@ import (
 )
 
 const (
-	repo           = "allthebacteria/atb-cli"
-	checkInterval  = 24 * time.Hour
-	stateFileName  = "update-state.json"
+	repo          = "allthebacteria/atb-cli"
+	checkInterval = 24 * time.Hour
+	stateFileName = "update-state.json"
 )
 
 type Release struct {