diff --git a/programs/pkey/rsa_decrypt.c b/programs/pkey/rsa_decrypt.c
index ff71bd0..3327909 100644
--- a/programs/pkey/rsa_decrypt.c
+++ b/programs/pkey/rsa_decrypt.c
@@ -160,7 +160,7 @@
 
     i = 0;
 
-    while( fscanf( f, "%02X", &c ) > 0 &&
+    while( fscanf( f, "%02X", (unsigned int*) &c ) > 0 &&
            i < (int) sizeof( buf ) )
         buf[i++] = (unsigned char) c;