diff --git a/.changeset/fix-architecture-label-width-floor.md b/.changeset/fix-architecture-label-width-floor.md
new file mode 100644
index 00000000000..8429822bea5
--- /dev/null
+++ b/.changeset/fix-architecture-label-width-floor.md
@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: floor architecture-beta service label width at 90px so long single-word labels (e.g. `ClickHouse`) no longer wrap mid-character at small `iconSize` values
diff --git a/cypress/integration/rendering/architecture/architecture.spec.ts b/cypress/integration/rendering/architecture/architecture.spec.ts
index dd52aa8cf9e..36d56681c4d 100644
--- a/cypress/integration/rendering/architecture/architecture.spec.ts
+++ b/cypress/integration/rendering/architecture/architecture.spec.ts
@@ -356,6 +356,24 @@ describe('architecture diagram', () => {
       { architecture: { randomize: true }, screenshot: false }
     );
   });
+  it('should keep long single-word service labels on one line at small iconSize', () => {
+    // Regression test for the label-width floor. At `iconSize: 50`, the
+    // historical width (`iconSize * 1.5 = 75px`) was too narrow to fit common
+    // single-word labels like "ClickHouse", causing mid-character wraps.
+    // The fix floors the label-area width at 90px so
+    // these labels stay on one line. Multi-word labels still wrap on word
+    // boundaries.
+    imgSnapshotTest(
+      `architecture-beta
+                service ch(database)[ClickHouse]
+                service pg(database)[Postgres]
+                service mb(server)[MessageBroker]
+                ch:R --> L:pg
+                pg:R --> L:mb
+            `,
+      { architecture: { iconSize: 50 } }
+    );
+  });
 });
 
 describe('architecture - fcose layout knobs', () => {
diff --git a/packages/mermaid/src/diagrams/architecture/svgDraw.ts b/packages/mermaid/src/diagrams/architecture/svgDraw.ts
index 3191123ae0a..de01f20517d 100644
--- a/packages/mermaid/src/diagrams/architecture/svgDraw.ts
+++ b/packages/mermaid/src/diagrams/architecture/svgDraw.ts
@@ -291,7 +291,11 @@ export const drawServices = async function (
         service.title,
         {
           useHtmlLabels: false,
-          width: iconSize * 1.5,
+          // Floor at 120px so long single-word labels (e.g. "ClickHouse", "MessageBroker")
+          // don't wrap mid-character at small iconSize. 120 matches the natural width at the
+          // default iconSize (80 * 1.5 = 120) — so the floor is a no-op at the default and
+          // only kicks in for iconSize values below 80.
+          width: Math.max(iconSize * 1.5, 120),
           classes: 'architecture-service-label',
         },
         config