diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
index cfeb8a4..3495d49 100644
--- a/library/hmac_drbg.c
+++ b/library/hmac_drbg.c
@@ -352,9 +352,8 @@
 
 #include <stdio.h>
 
-/*
- * Checkup routine
- */
+#if !defined(POLARSSL_SHA1_C)
+/* Dummy checkup routine */
 int hmac_drbg_self_test( int verbose )
 {
 
@@ -363,6 +362,112 @@
 
     return( 0 );
 }
+#else
+
+#define OUTPUT_LEN  80
+
+/* From a NIST PR=true test vector */
+static unsigned char entropy_pr[] = {
+    0xa0, 0xc9, 0xab, 0x58, 0xf1, 0xe2, 0xe5, 0xa4, 0xde, 0x3e, 0xbd, 0x4f,
+    0xf7, 0x3e, 0x9c, 0x5b, 0x64, 0xef, 0xd8, 0xca, 0x02, 0x8c, 0xf8, 0x11,
+    0x48, 0xa5, 0x84, 0xfe, 0x69, 0xab, 0x5a, 0xee, 0x42, 0xaa, 0x4d, 0x42,
+    0x17, 0x60, 0x99, 0xd4, 0x5e, 0x13, 0x97, 0xdc, 0x40, 0x4d, 0x86, 0xa3,
+    0x7b, 0xf5, 0x59, 0x54, 0x75, 0x69, 0x51, 0xe4 };
+static const unsigned char result_pr[OUTPUT_LEN] = {
+    0x9a, 0x00, 0xa2, 0xd0, 0x0e, 0xd5, 0x9b, 0xfe, 0x31, 0xec, 0xb1, 0x39,
+    0x9b, 0x60, 0x81, 0x48, 0xd1, 0x96, 0x9d, 0x25, 0x0d, 0x3c, 0x1e, 0x94,
+    0x10, 0x10, 0x98, 0x12, 0x93, 0x25, 0xca, 0xb8, 0xfc, 0xcc, 0x2d, 0x54,
+    0x73, 0x19, 0x70, 0xc0, 0x10, 0x7a, 0xa4, 0x89, 0x25, 0x19, 0x95, 0x5e,
+    0x4b, 0xc6, 0x00, 0x1d, 0x7f, 0x4e, 0x6a, 0x2b, 0xf8, 0xa3, 0x01, 0xab,
+    0x46, 0x05, 0x5c, 0x09, 0xa6, 0x71, 0x88, 0xf1, 0xa7, 0x40, 0xee, 0xf3,
+    0xe1, 0x5c, 0x02, 0x9b, 0x44, 0xaf, 0x03, 0x44 };
+
+/* From a NIST PR=false test vector */
+static unsigned char entropy_nopr[] = {
+    0x79, 0x34, 0x9b, 0xbf, 0x7c, 0xdd, 0xa5, 0x79, 0x95, 0x57, 0x86, 0x66,
+    0x21, 0xc9, 0x13, 0x83, 0x11, 0x46, 0x73, 0x3a, 0xbf, 0x8c, 0x35, 0xc8,
+    0xc7, 0x21, 0x5b, 0x5b, 0x96, 0xc4, 0x8e, 0x9b, 0x33, 0x8c, 0x74, 0xe3,
+    0xe9, 0x9d, 0xfe, 0xdf };
+static const unsigned char result_nopr[OUTPUT_LEN] = {
+    0xc6, 0xa1, 0x6a, 0xb8, 0xd4, 0x20, 0x70, 0x6f, 0x0f, 0x34, 0xab, 0x7f,
+    0xec, 0x5a, 0xdc, 0xa9, 0xd8, 0xca, 0x3a, 0x13, 0x3e, 0x15, 0x9c, 0xa6,
+    0xac, 0x43, 0xc6, 0xf8, 0xa2, 0xbe, 0x22, 0x83, 0x4a, 0x4c, 0x0a, 0x0a,
+    0xff, 0xb1, 0x0d, 0x71, 0x94, 0xf1, 0xc1, 0xa5, 0xcf, 0x73, 0x22, 0xec,
+    0x1a, 0xe0, 0x96, 0x4e, 0xd4, 0xbf, 0x12, 0x27, 0x46, 0xe0, 0x87, 0xfd,
+    0xb5, 0xb3, 0xe9, 0x1b, 0x34, 0x93, 0xd5, 0xbb, 0x98, 0xfa, 0xed, 0x49,
+    0xe8, 0x5f, 0x13, 0x0f, 0xc8, 0xa4, 0x59, 0xb7 };
+
+/* "Entropy" from buffer */
+static int test_offset;
+static int hmac_drbg_self_test_entropy( void *data,
+                                        unsigned char *buf, size_t len )
+{
+    const unsigned char *p = data;
+    memcpy( buf, p + test_offset, len );
+    test_offset += len;
+    return( 0 );
+}
+
+#define CHK( c )    if( (c) != 0 )                      \
+                    {                                   \
+                        if( verbose != 0 )              \
+                            printf( "failed\n" );       \
+                        return( 1 );                    \
+                    }
+
+/*
+ * Checkup routine for HMAC_DRBG with SHA-1
+ */
+int hmac_drbg_self_test( int verbose )
+{
+    hmac_drbg_context ctx;
+    unsigned char buf[OUTPUT_LEN];
+    const md_info_t *md_info = md_info_from_type( POLARSSL_MD_SHA1 );
+
+    /*
+     * PR = True
+     */
+    if( verbose != 0 )
+        printf( "  HMAC_DRBG (PR = True) : " );
+
+    test_offset = 0;
+    CHK( hmac_drbg_init( &ctx, md_info,
+                         hmac_drbg_self_test_entropy, entropy_pr,
+                         NULL, 0 ) );
+    hmac_drbg_set_prediction_resistance( &ctx, POLARSSL_HMAC_DRBG_PR_ON );
+    CHK( hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
+    CHK( hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
+    CHK( memcmp( buf, result_pr, OUTPUT_LEN ) );
+    hmac_drbg_free( &ctx );
+
+    if( verbose != 0 )
+        printf( "passed\n" );
+
+    /*
+     * PR = False
+     */
+    if( verbose != 0 )
+        printf( "  HMAC_DRBG (PR = False) : " );
+
+    test_offset = 0;
+    CHK( hmac_drbg_init( &ctx, md_info,
+                         hmac_drbg_self_test_entropy, entropy_nopr,
+                         NULL, 0 ) );
+    CHK( hmac_drbg_reseed( &ctx, NULL, 0 ) );
+    CHK( hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
+    CHK( hmac_drbg_random( &ctx, buf, OUTPUT_LEN ) );
+    CHK( memcmp( buf, result_nopr, OUTPUT_LEN ) );
+    hmac_drbg_free( &ctx );
+
+    if( verbose != 0 )
+        printf( "passed\n" );
+
+    if( verbose != 0 )
+            printf( "\n" );
+
+    return( 0 );
+}
+#endif /* POLARSSL_SHA1_C */
 #endif /* POLARSSL_SELF_TEST */
 
 #endif /* POLARSSL_HMAC_DRBG_C */