diff --git a/src/gc/unix/gcenv.unix.cpp b/src/gc/unix/gcenv.unix.cpp
index e64f62ac34d3..ed09e89f2641 100644
--- a/src/gc/unix/gcenv.unix.cpp
+++ b/src/gc/unix/gcenv.unix.cpp
@@ -449,7 +449,12 @@ the processors enabled.
 --*/
 static uintptr_t GetFullAffinityMask(int cpuCount)
 {
-    return ((uintptr_t)1 << (cpuCount)) - 1;
+    if (cpuCount < sizeof(uintptr_t) * 8)
+    {
+        return ((uintptr_t)1 << cpuCount) - 1;
+    }
+
+    return ~(uintptr_t)0;
 }
 
 // Get affinity mask of the current process
diff --git a/src/pal/src/numa/numa.cpp b/src/pal/src/numa/numa.cpp
index 92ec82f7495e..8793a09b8500 100644
--- a/src/pal/src/numa/numa.cpp
+++ b/src/pal/src/numa/numa.cpp
@@ -166,7 +166,12 @@ the processors enabled.
 --*/
 KAFFINITY GetFullAffinityMask(int cpuCount)
 {
-    return ((KAFFINITY)1 << (cpuCount)) - 1;
+    if (cpuCount < sizeof(KAFFINITY) * 8)
+    {
+        return ((KAFFINITY)1 << (cpuCount)) - 1;
+    }
+
+    return ~(KAFFINITY)0;
 }
 
 /*++