diff --git a/assets/js/hooks/Mapper/components/mapInterface/components/SystemLinkSignatureDialog/SystemLinkSignatureDialog.tsx b/assets/js/hooks/Mapper/components/mapInterface/components/SystemLinkSignatureDialog/SystemLinkSignatureDialog.tsx
index 574e9561..d816ac1d 100644
--- a/assets/js/hooks/Mapper/components/mapInterface/components/SystemLinkSignatureDialog/SystemLinkSignatureDialog.tsx
+++ b/assets/js/hooks/Mapper/components/mapInterface/components/SystemLinkSignatureDialog/SystemLinkSignatureDialog.tsx
@@ -146,7 +146,7 @@ export const SystemLinkSignatureDialog = ({ data, setVisible }: SystemLinkSignat
       }
 
       const whShipSize = getWhSize(wormholes, signature.type);
-      if (whShipSize) {
+      if (whShipSize !== undefined && whShipSize !== null) {
         await outCommand({
           type: OutCommand.updateConnectionShipSizeType,
           data: {
diff --git a/assets/js/hooks/Mapper/components/mapRootContent/components/SignatureSettings/SignatureSettings.tsx b/assets/js/hooks/Mapper/components/mapRootContent/components/SignatureSettings/SignatureSettings.tsx
index 4bc7adbb..1eb22ca9 100644
--- a/assets/js/hooks/Mapper/components/mapRootContent/components/SignatureSettings/SignatureSettings.tsx
+++ b/assets/js/hooks/Mapper/components/mapRootContent/components/SignatureSettings/SignatureSettings.tsx
@@ -67,8 +67,8 @@ export const SignatureSettings = ({ systemId, show, onHide, signatureData }: Map
 
             if (values.type) {
               const whShipSize = getWhSize(wormholes, values.type);
-              if (whShipSize) {
-                outCommand({
+              if (whShipSize !== undefined && whShipSize !== null) {
+                await outCommand({
                   type: OutCommand.updateConnectionShipSizeType,
                   data: {
                     source: systemId,