diff --git a/err_data.c b/err_data.c
index 7103cb1..b8f2816 100644
--- a/err_data.c
+++ b/err_data.c
@@ -214,25 +214,28 @@
     0x2c3bb277,
     0x2c3c1311,
     0x2c3c9327,
-    0x2c3d328b,
+    0x2c3d32bc,
     0x2c3d9340,
-    0x2c3e32a8,
-    0x2c3eb2b6,
-    0x2c3f32ce,
-    0x2c3fb2e6,
-    0x2c403310,
+    0x2c3e32e6,
+    0x2c3eb2f4,
+    0x2c3f330c,
+    0x2c3fb324,
+    0x2c40334e,
     0x2c409212,
-    0x2c413321,
-    0x2c41b334,
+    0x2c41335f,
+    0x2c41b372,
     0x2c4211d8,
-    0x2c42b345,
+    0x2c42b383,
     0x2c43072f,
     0x2c43b269,
     0x2c4431ca,
-    0x2c44b2f3,
+    0x2c44b331,
     0x2c453161,
     0x2c45b19d,
     0x2c463201,
+    0x2c46b28b,
+    0x2c4732a0,
+    0x2c47b2d9,
     0x30320000,
     0x30328015,
     0x3033001f,
@@ -664,69 +667,69 @@
     0x4c41156e,
     0x4c4193f1,
     0x4c42155a,
-    0x50323357,
-    0x5032b366,
-    0x50333371,
-    0x5033b381,
-    0x5034339a,
-    0x5034b3b4,
-    0x503533c2,
-    0x5035b3d8,
-    0x503633ea,
-    0x5036b400,
-    0x50373419,
-    0x5037b42c,
-    0x50383444,
-    0x5038b455,
-    0x5039346a,
-    0x5039b47e,
-    0x503a349e,
-    0x503ab4b4,
-    0x503b34cc,
-    0x503bb4de,
-    0x503c34fa,
-    0x503cb511,
-    0x503d352a,
-    0x503db540,
-    0x503e354d,
-    0x503eb563,
-    0x503f3575,
+    0x50323395,
+    0x5032b3a4,
+    0x503333af,
+    0x5033b3bf,
+    0x503433d8,
+    0x5034b3f2,
+    0x50353400,
+    0x5035b416,
+    0x50363428,
+    0x5036b43e,
+    0x50373457,
+    0x5037b46a,
+    0x50383482,
+    0x5038b493,
+    0x503934a8,
+    0x5039b4bc,
+    0x503a34dc,
+    0x503ab4f2,
+    0x503b350a,
+    0x503bb51c,
+    0x503c3538,
+    0x503cb54f,
+    0x503d3568,
+    0x503db57e,
+    0x503e358b,
+    0x503eb5a1,
+    0x503f35b3,
     0x503f8388,
-    0x50403588,
-    0x5040b598,
-    0x504135b2,
-    0x5041b5c1,
-    0x504235db,
-    0x5042b5f8,
-    0x50433608,
-    0x5043b618,
-    0x50443627,
+    0x504035c6,
+    0x5040b5d6,
+    0x504135f0,
+    0x5041b5ff,
+    0x50423619,
+    0x5042b636,
+    0x50433646,
+    0x5043b656,
+    0x50443665,
     0x5044843e,
-    0x5045363b,
-    0x5045b659,
-    0x5046366c,
-    0x5046b682,
-    0x50473694,
-    0x5047b6a9,
-    0x504836cf,
-    0x5048b6dd,
-    0x504936f0,
-    0x5049b705,
-    0x504a371b,
-    0x504ab72b,
-    0x504b374b,
-    0x504bb75e,
-    0x504c3781,
-    0x504cb7af,
-    0x504d37c1,
-    0x504db7de,
-    0x504e37f9,
-    0x504eb815,
-    0x504f3827,
-    0x504fb83e,
-    0x5050384d,
+    0x50453679,
+    0x5045b697,
+    0x504636aa,
+    0x5046b6c0,
+    0x504736d2,
+    0x5047b6e7,
+    0x5048370d,
+    0x5048b71b,
+    0x5049372e,
+    0x5049b743,
+    0x504a3759,
+    0x504ab769,
+    0x504b3789,
+    0x504bb79c,
+    0x504c37bf,
+    0x504cb7ed,
+    0x504d37ff,
+    0x504db81c,
+    0x504e3837,
+    0x504eb853,
+    0x504f3865,
+    0x504fb87c,
+    0x5050388b,
     0x505086fe,
-    0x50513860,
+    0x5051389e,
     0x58320f72,
     0x68320f34,
     0x68328c8c,
@@ -1385,7 +1388,10 @@
     "LOADING_DEFAULTS\0"
     "NAME_TOO_LONG\0"
     "NEWER_CRL_NOT_NEWER\0"
+    "NO_CERTIFICATE_FOUND\0"
+    "NO_CERTIFICATE_OR_CRL_FOUND\0"
     "NO_CERT_SET_FOR_US_TO_VERIFY\0"
+    "NO_CRL_FOUND\0"
     "NO_CRL_NUMBER\0"
     "PUBLIC_KEY_DECODE_ERROR\0"
     "PUBLIC_KEY_ENCODE_ERROR\0"
diff --git a/src/crypto/err/x509.errordata b/src/crypto/err/x509.errordata
index ffa4267..65181bf 100644
--- a/src/crypto/err/x509.errordata
+++ b/src/crypto/err/x509.errordata
@@ -25,8 +25,11 @@
 X509,119,NEWER_CRL_NOT_NEWER
 X509,120,NOT_PKCS7_SIGNED_DATA
 X509,121,NO_CERTIFICATES_INCLUDED
+X509,141,NO_CERTIFICATE_FOUND
+X509,142,NO_CERTIFICATE_OR_CRL_FOUND
 X509,122,NO_CERT_SET_FOR_US_TO_VERIFY
 X509,123,NO_CRLS_INCLUDED
+X509,143,NO_CRL_FOUND
 X509,124,NO_CRL_NUMBER
 X509,125,PUBLIC_KEY_DECODE_ERROR
 X509,126,PUBLIC_KEY_ENCODE_ERROR
diff --git a/src/crypto/x509/by_dir.c b/src/crypto/x509/by_dir.c
index 7b91cbd..f951218 100644
--- a/src/crypto/x509/by_dir.c
+++ b/src/crypto/x509/by_dir.c
@@ -437,6 +437,13 @@
                 ok = 1;
                 ret->type = tmp->type;
                 OPENSSL_memcpy(&ret->data, &tmp->data, sizeof(ret->data));
+
+                /*
+                 * Clear any errors that might have been raised processing empty
+                 * or malformed files.
+                 */
+                ERR_clear_error();
+
                 /*
                  * If we were going to up the reference count, we would need
                  * to do it on a perl 'type' basis
diff --git a/src/crypto/x509/by_file.c b/src/crypto/x509/by_file.c
index 994beb9..caf7d1e 100644
--- a/src/crypto/x509/by_file.c
+++ b/src/crypto/x509/by_file.c
@@ -124,8 +124,6 @@
     int i, count = 0;
     X509 *x = NULL;
 
-    if (file == NULL)
-        return (1);
     in = BIO_new(BIO_s_file());
 
     if ((in == NULL) || (BIO_read_filename(in, file) <= 0)) {
@@ -169,6 +167,11 @@
         OPENSSL_PUT_ERROR(X509, X509_R_BAD_X509_FILETYPE);
         goto err;
     }
+
+    if (ret == 0) {
+        OPENSSL_PUT_ERROR(X509, X509_R_NO_CERTIFICATE_FOUND);
+    }
+
  err:
     if (x != NULL)
         X509_free(x);
@@ -184,8 +187,6 @@
     int i, count = 0;
     X509_CRL *x = NULL;
 
-    if (file == NULL)
-        return (1);
     in = BIO_new(BIO_s_file());
 
     if ((in == NULL) || (BIO_read_filename(in, file) <= 0)) {
@@ -229,6 +230,11 @@
         OPENSSL_PUT_ERROR(X509, X509_R_BAD_X509_FILETYPE);
         goto err;
     }
+
+    if (ret == 0) {
+        OPENSSL_PUT_ERROR(X509, X509_R_NO_CRL_FOUND);
+    }
+
  err:
     if (x != NULL)
         X509_CRL_free(x);
@@ -244,6 +250,7 @@
     BIO *in;
     size_t i;
     int count = 0;
+
     if (type != X509_FILETYPE_PEM)
         return X509_load_cert_file(ctx, file, type);
     in = BIO_new_file(file, "r");
@@ -260,14 +267,24 @@
     for (i = 0; i < sk_X509_INFO_num(inf); i++) {
         itmp = sk_X509_INFO_value(inf, i);
         if (itmp->x509) {
-            X509_STORE_add_cert(ctx->store_ctx, itmp->x509);
+            if (!X509_STORE_add_cert(ctx->store_ctx, itmp->x509)) {
+                goto err;
+            }
             count++;
         }
         if (itmp->crl) {
-            X509_STORE_add_crl(ctx->store_ctx, itmp->crl);
+            if (!X509_STORE_add_crl(ctx->store_ctx, itmp->crl)) {
+                goto err;
+            }
             count++;
         }
     }
+
+    if (count == 0) {
+        OPENSSL_PUT_ERROR(X509, X509_R_NO_CERTIFICATE_OR_CRL_FOUND);
+    }
+
+err:
     sk_X509_INFO_pop_free(inf, X509_INFO_free);
     return count;
 }
diff --git a/src/crypto/x509/x509_lu.c b/src/crypto/x509/x509_lu.c
index 4046c3e..36a482e 100644
--- a/src/crypto/x509/x509_lu.c
+++ b/src/crypto/x509/x509_lu.c
@@ -331,76 +331,54 @@
     return 1;
 }
 
-int X509_STORE_add_cert(X509_STORE *ctx, X509 *x)
+static int x509_store_add(X509_STORE *ctx, void *x, int is_crl)
 {
-    X509_OBJECT *obj;
-    int ret = 1;
-
-    if (x == NULL)
+    if (x == NULL) {
         return 0;
-    obj = (X509_OBJECT *)OPENSSL_malloc(sizeof(X509_OBJECT));
+    }
+
+    X509_OBJECT *const obj = (X509_OBJECT *)OPENSSL_malloc(sizeof(X509_OBJECT));
     if (obj == NULL) {
         OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
         return 0;
     }
-    obj->type = X509_LU_X509;
-    obj->data.x509 = x;
+
+    if (is_crl) {
+        obj->type = X509_LU_CRL;
+        obj->data.crl = (X509_CRL *)x;
+    } else {
+        obj->type = X509_LU_X509;
+        obj->data.x509 = (X509 *)x;
+    }
+    X509_OBJECT_up_ref_count(obj);
 
     CRYPTO_MUTEX_lock_write(&ctx->objs_lock);
 
-    X509_OBJECT_up_ref_count(obj);
-
-    if (X509_OBJECT_retrieve_match(ctx->objs, obj)) {
-        X509_OBJECT_free_contents(obj);
-        OPENSSL_free(obj);
-        OPENSSL_PUT_ERROR(X509, X509_R_CERT_ALREADY_IN_HASH_TABLE);
-        ret = 0;
-    } else if (!sk_X509_OBJECT_push(ctx->objs, obj)) {
-        X509_OBJECT_free_contents(obj);
-        OPENSSL_free(obj);
-        OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
-        ret = 0;
+    int ret = 1;
+    int added = 0;
+    /* Duplicates are silently ignored */
+    if (!X509_OBJECT_retrieve_match(ctx->objs, obj)) {
+        ret = added = (sk_X509_OBJECT_push(ctx->objs, obj) != 0);
     }
 
     CRYPTO_MUTEX_unlock_write(&ctx->objs_lock);
 
+    if (!added) {
+        X509_OBJECT_free_contents(obj);
+        OPENSSL_free(obj);
+    }
+
     return ret;
 }
 
+int X509_STORE_add_cert(X509_STORE *ctx, X509 *x)
+{
+    return x509_store_add(ctx, x, /*is_crl=*/0);
+}
+
 int X509_STORE_add_crl(X509_STORE *ctx, X509_CRL *x)
 {
-    X509_OBJECT *obj;
-    int ret = 1;
-
-    if (x == NULL)
-        return 0;
-    obj = (X509_OBJECT *)OPENSSL_malloc(sizeof(X509_OBJECT));
-    if (obj == NULL) {
-        OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
-        return 0;
-    }
-    obj->type = X509_LU_CRL;
-    obj->data.crl = x;
-
-    CRYPTO_MUTEX_lock_write(&ctx->objs_lock);
-
-    X509_OBJECT_up_ref_count(obj);
-
-    if (X509_OBJECT_retrieve_match(ctx->objs, obj)) {
-        X509_OBJECT_free_contents(obj);
-        OPENSSL_free(obj);
-        OPENSSL_PUT_ERROR(X509, X509_R_CERT_ALREADY_IN_HASH_TABLE);
-        ret = 0;
-    } else if (!sk_X509_OBJECT_push(ctx->objs, obj)) {
-        X509_OBJECT_free_contents(obj);
-        OPENSSL_free(obj);
-        OPENSSL_PUT_ERROR(X509, ERR_R_MALLOC_FAILURE);
-        ret = 0;
-    }
-
-    CRYPTO_MUTEX_unlock_write(&ctx->objs_lock);
-
-    return ret;
+    return x509_store_add(ctx, x, /*is_crl=*/1);
 }
 
 void X509_STORE_set0_additional_untrusted(X509_STORE *ctx,
diff --git a/src/crypto/x509/x509_test.cc b/src/crypto/x509/x509_test.cc
index bde4339..373f67a 100644
--- a/src/crypto/x509/x509_test.cc
+++ b/src/crypto/x509/x509_test.cc
@@ -2994,3 +2994,22 @@
     }
   }
 }
+
+TEST(X509Test, AddDuplicates) {
+  bssl::UniquePtr<X509_STORE> store(X509_STORE_new());
+  bssl::UniquePtr<X509> a(CertFromPEM(kCrossSigningRootPEM));
+  bssl::UniquePtr<X509> b(CertFromPEM(kRootCAPEM));
+
+  ASSERT_TRUE(store);
+  ASSERT_TRUE(a);
+  ASSERT_TRUE(b);
+
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), a.get()));
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), b.get()));
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), a.get()));
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), b.get()));
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), a.get()));
+  EXPECT_TRUE(X509_STORE_add_cert(store.get(), b.get()));
+
+  EXPECT_EQ(sk_X509_OBJECT_num(X509_STORE_get0_objects(store.get())), 2u);
+}
diff --git a/src/include/openssl/x509.h b/src/include/openssl/x509.h
index a75442f..9b45b4b 100644
--- a/src/include/openssl/x509.h
+++ b/src/include/openssl/x509.h
@@ -1587,5 +1587,8 @@
 #define X509_R_DELTA_CRL_WITHOUT_CRL_NUMBER 138
 #define X509_R_INVALID_FIELD_FOR_VERSION 139
 #define X509_R_INVALID_VERSION 140
+#define X509_R_NO_CERTIFICATE_FOUND 141
+#define X509_R_NO_CERTIFICATE_OR_CRL_FOUND 142
+#define X509_R_NO_CRL_FOUND 143
 
 #endif