diff --git a/apps/web/src/components/Form/FormInput.test.tsx b/apps/web/src/components/Form/FormInput.test.tsx
new file mode 100644
index 000000000..0ea2f5ede
--- /dev/null
+++ b/apps/web/src/components/Form/FormInput.test.tsx
@@ -0,0 +1,94 @@
+import { PositionValidationSchema } from "@app/validation/config/position.ts";
+import { render, screen } from "@testing-library/react";
+import userEvent from "@testing-library/user-event";
+import { useForm } from "react-hook-form";
+import { describe, expect, it } from "vitest";
+import { GenericInput, type InputFieldProps } from "./FormInput.tsx";
+
+type LatitudeForm = { latitude: number | undefined };
+
+/**
+ * Mirrors how Position.tsx uses the latitude field: an optional numeric value
+ * that starts out `undefined` when the node has no fixed position. The stored
+ * form value is echoed into a test-only node, since the bug in #1308 was about
+ * what the field committed, not only what it displayed.
+ */
+function Harness({
+  properties,
+}: {
+  properties: InputFieldProps<LatitudeForm>["properties"];
+}) {
+  const { control, watch } = useForm<LatitudeForm>({
+    defaultValues: { latitude: undefined },
+  });
+
+  return (
+    <>
+      <GenericInput<LatitudeForm>
+        control={control}
+        field={{
+          type: "number",
+          name: "latitude",
+          label: "Latitude",
+          properties,
+        }}
+      />
+      <output data-testid="stored">{String(watch("latitude"))}</output>
+    </>
+  );
+}
+
+// Matches the real latitude/longitude field config in Position.tsx.
+const latitudeProperties = { step: 0.0000001, fieldLength: { max: 12 } };
+
+/** GenericInput renders no <label> of its own, so address the input by its id. */
+const getInput = () => document.getElementById("latitude") as HTMLInputElement;
+
+const stored = () => screen.getByTestId("stored").textContent;
+
+describe("GenericInput - negative coordinates (issue #1308)", () => {
+  it("accepts a pasted negative latitude", async () => {
+    const user = userEvent.setup();
+    render(<Harness properties={latitudeProperties} />);
+
+    await user.click(getInput());
+    await user.paste("-34.1147648");
+
+    expect(stored()).toBe("-34.1147648");
+  });
+
+  it("accepts a negative latitude typed one key at a time", async () => {
+    const user = userEvent.setup();
+    render(<Harness properties={latitudeProperties} />);
+
+    await user.type(getInput(), "-34.1147648");
+
+    expect(stored()).toBe("-34.1147648");
+  });
+
+  it("still accepts a positive latitude", async () => {
+    const user = userEvent.setup();
+    render(<Harness properties={latitudeProperties} />);
+
+    await user.click(getInput());
+    await user.paste("34.1147648");
+
+    expect(stored()).toBe("34.1147648");
+  });
+
+  it("still rejects input longer than fieldLength.max", async () => {
+    const user = userEvent.setup();
+    render(<Harness properties={latitudeProperties} />);
+
+    await user.click(getInput());
+    await user.paste("-1234.567890123");
+
+    expect(stored()).toBe("undefined");
+  });
+
+  it("validates a negative latitude against the position schema", () => {
+    expect(PositionValidationSchema.shape.latitude.parse("-34.1147648")).toBe(
+      -34.1147648,
+    );
+  });
+});
diff --git a/apps/web/src/components/Form/FormInput.tsx b/apps/web/src/components/Form/FormInput.tsx
index 487f96569..259c3ae45 100644
--- a/apps/web/src/components/Form/FormInput.tsx
+++ b/apps/web/src/components/Form/FormInput.tsx
@@ -75,11 +75,7 @@ export function GenericInput<T extends FieldValues>({
       <Input
         type={field.type}
         step={field.properties?.step}
-        value={
-          field.type === "number"
-            ? String(controllerField.value)
-            : controllerField.value
-        }
+        value={controllerField.value ?? ""}
         id={field.name}
         onChange={handleInputChange}
         showCopyButton={field.properties?.showCopyButton}
diff --git a/apps/web/src/components/PageComponents/Settings/Position.tsx b/apps/web/src/components/PageComponents/Settings/Position.tsx
index c61674695..77ea7087a 100644
--- a/apps/web/src/components/PageComponents/Settings/Position.tsx
+++ b/apps/web/src/components/PageComponents/Settings/Position.tsx
@@ -236,7 +236,7 @@ export const Position = ({ onFormInit }: PositionConfigProps) => {
               properties: {
                 step: 0.0000001,
                 suffix: "Degrees",
-                fieldLength: { max: 10 },
+                fieldLength: { max: 12 },
               },
               disabledBy: [{ fieldName: "fixedPosition" }],
             },
@@ -248,7 +248,7 @@ export const Position = ({ onFormInit }: PositionConfigProps) => {
               properties: {
                 step: 0.0000001,
                 suffix: "Degrees",
-                fieldLength: { max: 10 },
+                fieldLength: { max: 12 },
               },
               disabledBy: [{ fieldName: "fixedPosition" }],
             },