diff --git a/common/mempool.c b/common/mempool.c
index fac3229c2..b442a0ffb 100644
--- a/common/mempool.c
+++ b/common/mempool.c
@@ -29,7 +29,7 @@ extern "C" {
 
 typedef struct MemPoolEntry {
     struct MemPoolEntry* next;
-    char* fileName;
+    const char* fileName;
     XP_U32 lineNo;
     XP_U32 size;
     void* ptr;
@@ -120,7 +120,7 @@ mpool_destroy( MemPoolCtx* mpool )
 } /* mpool_destroy */
 
 void*
-mpool_alloc( MemPoolCtx* mpool, XP_U32 size, char* file, XP_U32 lineNo )
+mpool_alloc( MemPoolCtx* mpool, XP_U32 size, const char* file, XP_U32 lineNo )
 {
     MemPoolEntry* entry;
 
diff --git a/common/mempool.h b/common/mempool.h
index fb92a968f..4565dfac3 100644
--- a/common/mempool.h
+++ b/common/mempool.h
@@ -33,8 +33,8 @@ typedef struct MemPoolCtx MemPoolCtx;
 MemPoolCtx* mpool_make();
 void mpool_destroy( MemPoolCtx* mpool );
 
-void* mpool_alloc( MemPoolCtx* mpool, XP_U32 size, char* file, 
-		   XP_U32 lineNo );
+void* mpool_alloc( MemPoolCtx* mpool, XP_U32 size, 
+                   const char* file, XP_U32 lineNo );
 void* mpool_realloc( MemPoolCtx* mpool, void* ptr, XP_U32 newsize );
 void mpool_free( MemPoolCtx* mpool, void* ptr );
 void mpool_stats( MemPoolCtx* mpool, XWStreamCtxt* stream );