diff --git a/jOOQ/src/main/java/org/jooq/impl/SQLDataType.java b/jOOQ/src/main/java/org/jooq/impl/SQLDataType.java
index 2f0c1d6f07..86695c56ff 100644
--- a/jOOQ/src/main/java/org/jooq/impl/SQLDataType.java
+++ b/jOOQ/src/main/java/org/jooq/impl/SQLDataType.java
@@ -96,6 +96,7 @@ import org.jooq.util.sqlite.SQLiteDataType;
  *
  * @author Lukas Eder
  */
+@SuppressWarnings("deprecation")
 public final class SQLDataType {
 
     // -------------------------------------------------------------------------
@@ -579,7 +580,7 @@ public final class SQLDataType {
 
     static {
         // Load all dialect-specific data types
-        // TODO [#650] Make this more reliable using a data type registry
+        // TODO [#5713] Make this more reliable using a data type registry
 
         try {
 
diff --git a/jOOQ/src/main/java/org/jooq/util/cubrid/CUBRIDDataType.java b/jOOQ/src/main/java/org/jooq/util/cubrid/CUBRIDDataType.java
index e37376776e..b5e5be9024 100644
--- a/jOOQ/src/main/java/org/jooq/util/cubrid/CUBRIDDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/cubrid/CUBRIDDataType.java
@@ -58,7 +58,14 @@ import org.jooq.types.UShort;
  * Supported data types for the {@link SQLDialect#CUBRID} dialect
  *
  * @author Lukas Eder
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class CUBRIDDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/derby/DerbyDataType.java b/jOOQ/src/main/java/org/jooq/util/derby/DerbyDataType.java
index aa0d7ca47a..dc3bbb3196 100644
--- a/jOOQ/src/main/java/org/jooq/util/derby/DerbyDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/derby/DerbyDataType.java
@@ -59,7 +59,14 @@ import org.jooq.types.UShort;
  *
  * @author Lukas Eder
  * @see <a href="http://db.apache.org/derby/docs/10.7/ref/crefsqlj31068.html">http://db.apache.org/derby/docs/10.7/ref/crefsqlj31068.html</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class DerbyDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java b/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
index 77a2f23faf..7acf8c5ce4 100644
--- a/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/firebird/FirebirdDataType.java
@@ -60,7 +60,14 @@ import org.jooq.types.YearToMonth;
  * Supported data types for the {@link SQLDialect#FIREBIRD} dialect
  *
  * @author Lukas Eder
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class FirebirdDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/h2/H2DataType.java b/jOOQ/src/main/java/org/jooq/util/h2/H2DataType.java
index f2a27d122d..9c17036cf6 100644
--- a/jOOQ/src/main/java/org/jooq/util/h2/H2DataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/h2/H2DataType.java
@@ -61,7 +61,14 @@ import org.jooq.types.UShort;
  *
  * @author Lukas Eder
  * @see <a href="http://www.h2database.com/html/datatypes.html">http://www.h2database.com/html/datatypes.html</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class H2DataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/hsqldb/HSQLDBDataType.java b/jOOQ/src/main/java/org/jooq/util/hsqldb/HSQLDBDataType.java
index 3a52fe1d08..cd027b3779 100644
--- a/jOOQ/src/main/java/org/jooq/util/hsqldb/HSQLDBDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/hsqldb/HSQLDBDataType.java
@@ -64,7 +64,14 @@ import org.jooq.types.YearToMonth;
  * @author Lukas Eder
  * @see <a href="http://hsqldb.org/doc/guide/ch09.html#datatypes-section">http://hsqldb.org/doc/guide/ch09.html#datatypes-section</a>
  * @see <a href="http://hsqldb.org/doc/2.0/guide/sqlgeneral-chapt.html#sqlgeneral_types_ops-sect">http://hsqldb.org/doc/2.0/guide/sqlgeneral-chapt.html#sqlgeneral_types_ops-sect</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class HSQLDBDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/mariadb/MariaDBDataType.java b/jOOQ/src/main/java/org/jooq/util/mariadb/MariaDBDataType.java
index 0385e5784c..7e0ca035f6 100644
--- a/jOOQ/src/main/java/org/jooq/util/mariadb/MariaDBDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/mariadb/MariaDBDataType.java
@@ -60,7 +60,14 @@ import org.jooq.types.UShort;
  * @author Lukas Eder
  * @see <a href="http://dev.mysql.com/doc/refman/5.5/en/data-types.html">http://dev.mysql.com/doc/refman/5.5/en/data-types.html</a>
  * @see <a href="http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html#function_cast">http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html#function_cast</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class MariaDBDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/mysql/MySQLDataType.java b/jOOQ/src/main/java/org/jooq/util/mysql/MySQLDataType.java
index 2219f09d33..a92c54c55b 100644
--- a/jOOQ/src/main/java/org/jooq/util/mysql/MySQLDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/mysql/MySQLDataType.java
@@ -60,7 +60,14 @@ import org.jooq.types.UShort;
  * @author Lukas Eder
  * @see <a href="http://dev.mysql.com/doc/refman/5.5/en/data-types.html">http://dev.mysql.com/doc/refman/5.5/en/data-types.html</a>
  * @see <a href="http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html#function_cast">http://dev.mysql.com/doc/refman/5.5/en/cast-functions.html#function_cast</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class MySQLDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/postgres/PostgresDataType.java b/jOOQ/src/main/java/org/jooq/util/postgres/PostgresDataType.java
index c68eef7c75..31656fb8bb 100644
--- a/jOOQ/src/main/java/org/jooq/util/postgres/PostgresDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/postgres/PostgresDataType.java
@@ -65,7 +65,14 @@ import org.jooq.types.YearToMonth;
  *
  * @author Lukas Eder
  * @see <a href="http://www.postgresql.org/docs/9.0/interactive/datatype.html">http://www.postgresql.org/docs/9.0/interactive/datatype.html</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class PostgresDataType {
 
     // -------------------------------------------------------------------------
diff --git a/jOOQ/src/main/java/org/jooq/util/sqlite/SQLiteDataType.java b/jOOQ/src/main/java/org/jooq/util/sqlite/SQLiteDataType.java
index 844c502755..1321a91da4 100644
--- a/jOOQ/src/main/java/org/jooq/util/sqlite/SQLiteDataType.java
+++ b/jOOQ/src/main/java/org/jooq/util/sqlite/SQLiteDataType.java
@@ -58,7 +58,14 @@ import org.jooq.types.UShort;
  *
  * @author Lukas Eder
  * @see <a href="http://www.sqlite.org/datatype3.html">http://www.sqlite.org/datatype3.html</a>
+ * @deprecated - 3.11.0 - [#7375] - This type is part of jOOQ's internal API. Do
+ *             not reference this type directly from client code. Referencing
+ *             this type before the {@link SQLDataType} class has been
+ *             initialised may lead to deadlocks! See <a href=
+ *             "https://github.com/jOOQ/jOOQ/issues/3777">https://github.com/jOOQ/jOOQ/issues/3777</a>
+ *             for details.
  */
+@Deprecated
 public class SQLiteDataType {
 
     // -------------------------------------------------------------------------