diff --git a/library/rsa.c b/library/rsa.c
index 11ba201..d866c7a 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -447,14 +447,19 @@
 
     /* Sanity-check that all relevant fields are at least set,
      * but don't perform a full keycheck. */
+#if defined(MBEDTLS_RSA_NO_CRT)
     if( mbedtls_mpi_cmp_int( &ctx->N, 0 ) == 0 ||
         mbedtls_mpi_cmp_int( &ctx->D, 0 ) == 0 ||
-        mbedtls_mpi_cmp_int( &ctx->E, 0 ) == 0 )
+        mbedtls_mpi_cmp_int( &ctx->E, 0 ) == 0 ||
+        mbedtls_mpi_cmp_int( &ctx->P, 0 ) == 0 ||
+        mbedtls_mpi_cmp_int( &ctx->Q, 0 ) == 0 )
     {
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
     }
-#if !defined(MBEDTLS_RSA_NO_CRT)
-    if( mbedtls_mpi_cmp_int( &ctx->P, 0 )  == 0 ||
+#else /* ! MBEDTLS_RSA_NO_CRT */
+    if( mbedtls_mpi_cmp_int( &ctx->N, 0 )  == 0 ||
+        mbedtls_mpi_cmp_int( &ctx->E, 0 )  == 0 ||
+        mbedtls_mpi_cmp_int( &ctx->P, 0 )  == 0 ||
         mbedtls_mpi_cmp_int( &ctx->Q, 0 )  == 0 ||
         mbedtls_mpi_cmp_int( &ctx->DP, 0 ) == 0 ||
         mbedtls_mpi_cmp_int( &ctx->DQ, 0 ) == 0 ||
@@ -462,7 +467,7 @@
     {
         return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
     }
-#endif /* MBEDTLS_RSA_NO_CRT */
+#endif /* ! MBEDTLS_RSA_NO_CRT */
 
 #if defined(MBEDTLS_THREADING_C)
     if( ( ret = mbedtls_mutex_lock( &ctx->mutex ) ) != 0 )