diff --git a/src/app/api/tournaments/[id]/games/bulk/route.ts b/src/app/api/tournaments/[id]/games/bulk/route.ts
index 841b710..bdd342a 100644
--- a/src/app/api/tournaments/[id]/games/bulk/route.ts
+++ b/src/app/api/tournaments/[id]/games/bulk/route.ts
@@ -11,7 +11,15 @@ export async function POST(
   { params }: { params: { id: string } }
 ) {
   try {
-    const tournamentId = parseInt(params.id);
+    const tournamentId = parseInt(params.id, 10);
+    
+    if (isNaN(tournamentId)) {
+      return NextResponse.json(
+        { error: "Invalid tournament ID" },
+        { status: 400 }
+      );
+    }
+    
     const body = await request.json();
     const { games } = body;
 
diff --git a/src/app/api/tournaments/[id]/participants/route.ts b/src/app/api/tournaments/[id]/participants/route.ts
index 593c934..63c5292 100644
--- a/src/app/api/tournaments/[id]/participants/route.ts
+++ b/src/app/api/tournaments/[id]/participants/route.ts
@@ -7,7 +7,15 @@ export async function POST(
   { params }: { params: { id: string } }
 ) {
   try {
-    const tournamentId = parseInt(params.id);
+    const tournamentId = parseInt(params.id, 10);
+    
+    if (isNaN(tournamentId)) {
+      return NextResponse.json(
+        { error: "Invalid tournament ID" },
+        { status: 400 }
+      );
+    }
+    
     const body = await request.json();
     const { playerIds } = body;
 
diff --git a/src/app/players/[id]/profile/page.tsx b/src/app/players/[id]/profile/page.tsx
index 6aa17b5..2422889 100644
--- a/src/app/players/[id]/profile/page.tsx
+++ b/src/app/players/[id]/profile/page.tsx
@@ -10,7 +10,11 @@ interface PageProps {
 }
 
 export default async function PlayerProfilePage({ params }: PageProps) {
-  const playerId = parseInt(params.id)
+  const playerId = parseInt(params.id, 10)
+  
+  if (isNaN(playerId)) {
+    notFound()
+  }
 
   const player = await prisma.player.findUnique({
     where: { id: playerId },
diff --git a/src/app/players/[id]/schedule/page.tsx b/src/app/players/[id]/schedule/page.tsx
index 95b9449..8548000 100644
--- a/src/app/players/[id]/schedule/page.tsx
+++ b/src/app/players/[id]/schedule/page.tsx
@@ -10,7 +10,11 @@ interface PageProps {
 }
 
 export default async function PlayerSchedulePage({ params }: PageProps) {
-  const playerId = parseInt(params.id)
+  const playerId = parseInt(params.id, 10)
+  
+  if (isNaN(playerId)) {
+    notFound()
+  }
 
   const player = await prisma.player.findUnique({
     where: { id: playerId },