diff --git a/ChangeLog.d/remove_allow_sha1_in_certificates b/ChangeLog.d/remove_allow_sha1_in_certificates
new file mode 100644
index 0000000..e3d16ef
--- /dev/null
+++ b/ChangeLog.d/remove_allow_sha1_in_certificates
@@ -0,0 +1,14 @@
+Removals
+   * Remove the MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
+     compile-time option, which was off by default. Users should not trust
+     certificates signed with SHA-1 due to the known attacks against SHA-1.
+     If needed, SHA-1 cerificate can still be used by providing custom
+     verification profile to mbedtls_x509_crt_verify_with_profile function
+     in x509_crt.h, or mbedtls_ssl_conf_cert_profile function in ssl.h.
+     Example of custom verification profile, supporting SHA-1:
+     const mbedtls_x509_crt_profile mbedtls_x509_crt_custom = {
+         MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ),
+         0xFFFFFFF, /* Any PK alg    */
+         0xFFFFFFF, /* Any curve     */
+         2048
+     };
diff --git a/configs/config-psa-crypto.h b/configs/config-psa-crypto.h
index 42dcbb1..2047bc4 100644
--- a/configs/config-psa-crypto.h
+++ b/configs/config-psa-crypto.h
@@ -3129,20 +3129,6 @@
 //#define MBEDTLS_X509_MAX_FILE_PATH_LEN     512 /**< Maximum length of a path/filename string in bytes including the null terminator character ('\0'). */
 
 /**
- * Allow SHA-1 in the default TLS configuration for certificate signing.
- * Without this build-time option, SHA-1 support must be activated explicitly
- * through mbedtls_ssl_conf_cert_profile. Turning on this option is not
- * recommended because of it is possible to generate SHA-1 collisions, however
- * this may be safe for legacy infrastructure where additional controls apply.
- *
- * \warning   SHA-1 is considered a weak message digest and its use constitutes
- *            a security risk. If possible, we recommend avoiding dependencies
- *            on it, and considering stronger message digests instead.
- *
- */
-// #define MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-
-/**
  * Allow SHA-1 in the default TLS configuration for TLS 1.2 handshake
  * signature and ciphersuite selection. Without this build-time option, SHA-1
  * support must be activated explicitly through mbedtls_ssl_conf_sig_hashes.
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index f760646..3f5f533 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -3701,20 +3701,6 @@
 //#define MBEDTLS_X509_MAX_FILE_PATH_LEN     512 /**< Maximum length of a path/filename string in bytes including the null terminator character ('\0'). */
 
 /**
- * Allow SHA-1 in the default TLS configuration for certificate signing.
- * Without this build-time option, SHA-1 support must be activated explicitly
- * through mbedtls_ssl_conf_cert_profile. Turning on this option is not
- * recommended because of it is possible to generate SHA-1 collisions, however
- * this may be safe for legacy infrastructure where additional controls apply.
- *
- * \warning   SHA-1 is considered a weak message digest and its use constitutes
- *            a security risk. If possible, we recommend avoiding dependencies
- *            on it, and considering stronger message digests instead.
- *
- */
-//#define MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-
-/**
  * Allow SHA-1 in the default TLS configuration for TLS 1.2 handshake
  * signature and ciphersuite selection. Without this build-time option, SHA-1
  * support must be activated explicitly through mbedtls_ssl_conf_sig_hashes.
diff --git a/library/x509_crt.c b/library/x509_crt.c
index 0aa4f4c..783f3ba 100644
--- a/library/x509_crt.c
+++ b/library/x509_crt.c
@@ -96,10 +96,6 @@
  */
 const mbedtls_x509_crt_profile mbedtls_x509_crt_profile_default =
 {
-#if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
-    /* Allow SHA-1 (weak, but still safe in controlled environments) */
-    MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA1 ) |
-#endif
     /* Only SHA-2 hashes */
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA224 ) |
     MBEDTLS_X509_ID_FLAG( MBEDTLS_MD_SHA256 ) |
diff --git a/programs/test/query_config.c b/programs/test/query_config.c
index 4ddc473..350f35f 100644
--- a/programs/test/query_config.c
+++ b/programs/test/query_config.c
@@ -2692,14 +2692,6 @@
     }
 #endif /* MBEDTLS_X509_MAX_FILE_PATH_LEN */
 
-#if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES)
-    if( strcmp( "MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES", config ) == 0 )
-    {
-        MACRO_EXPANSION_TO_STR( MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES );
-        return( 0 );
-    }
-#endif /* MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES */
-
 #if defined(MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE)
     if( strcmp( "MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_KEY_EXCHANGE", config ) == 0 )
     {
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index eae62fa..b01c226 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2499,15 +2499,6 @@
     armc6_build_test "--target=aarch64-arm-none-eabi -march=armv8.2-a"
 }
 
-component_test_allow_sha1 () {
-    msg "build: allow SHA1 in certificates by default"
-    scripts/config.py set MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-    make CFLAGS='-Werror -Wall -Wextra'
-    msg "test: allow SHA1 in certificates by default"
-    make test
-    if_build_succeeded tests/ssl-opt.sh -f SHA-1
-}
-
 component_test_tls13_experimental () {
     msg "build: default config with MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL enabled"
     scripts/config.pl set MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index b16d195..db898cf 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1419,20 +1419,12 @@
             0
 
 # Tests for SHA-1 support
-
-requires_config_disabled MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
 run_test    "SHA-1 forbidden by default in server certificate" \
             "$P_SRV key_file=data_files/server2.key crt_file=data_files/server2.crt" \
             "$P_CLI debug_level=2 allow_sha1=0" \
             1 \
             -c "The certificate is signed with an unacceptable hash"
 
-requires_config_enabled MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-run_test    "SHA-1 allowed by default in server certificate" \
-            "$P_SRV key_file=data_files/server2.key crt_file=data_files/server2.crt" \
-            "$P_CLI debug_level=2 allow_sha1=0" \
-            0
-
 run_test    "SHA-1 explicitly allowed in server certificate" \
             "$P_SRV key_file=data_files/server2.key crt_file=data_files/server2.crt" \
             "$P_CLI allow_sha1=1" \
@@ -1443,19 +1435,12 @@
             "$P_CLI allow_sha1=0" \
             0
 
-requires_config_disabled MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
 run_test    "SHA-1 forbidden by default in client certificate" \
             "$P_SRV auth_mode=required allow_sha1=0" \
             "$P_CLI key_file=data_files/cli-rsa.key crt_file=data_files/cli-rsa-sha1.crt" \
             1 \
             -s "The certificate is signed with an unacceptable hash"
 
-requires_config_enabled MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-run_test    "SHA-1 allowed by default in client certificate" \
-            "$P_SRV auth_mode=required allow_sha1=0" \
-            "$P_CLI key_file=data_files/cli-rsa.key crt_file=data_files/cli-rsa-sha1.crt" \
-            0
-
 run_test    "SHA-1 explicitly allowed in client certificate" \
             "$P_SRV auth_mode=required allow_sha1=1" \
             "$P_CLI key_file=data_files/cli-rsa.key crt_file=data_files/cli-rsa-sha1.crt" \
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index 5229906..0cc1d3f 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -559,12 +559,8 @@
 depends_on:MBEDTLS_SHA1_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
 x509_verify:"data_files/cert_sha1.crt":"data_files/test-ca.crt":"data_files/crl.pem":"NULL":0:0:"compat":"NULL"
 
-X509 CRT verification #14 (Valid Cert SHA1 Digest allowed in compile-time default profile)
-depends_on:MBEDTLS_SHA1_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
-x509_verify:"data_files/cert_sha1.crt":"data_files/test-ca.crt":"data_files/crl.pem":"NULL":0:0:"":"NULL"
-
 X509 CRT verification #14 (Valid Cert SHA1 Digest forbidden in default profile)
-depends_on:MBEDTLS_SHA1_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15:!MBEDTLS_TLS_DEFAULT_ALLOW_SHA1_IN_CERTIFICATES
+depends_on:MBEDTLS_SHA1_C:MBEDTLS_PEM_PARSE_C:MBEDTLS_SHA1_C:MBEDTLS_RSA_C:MBEDTLS_PKCS1_V15
 x509_verify:"data_files/cert_sha1.crt":"data_files/test-ca.crt":"data_files/crl.pem":"NULL":MBEDTLS_ERR_X509_CERT_VERIFY_FAILED:MBEDTLS_X509_BADCRL_BAD_MD | MBEDTLS_X509_BADCERT_BAD_MD:"":"NULL"
 
 X509 CRT verification #15 (Valid Cert SHA224 Digest)