diff --git a/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt b/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
index eaf54da61d..c30618caf5 100644
--- a/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
+++ b/jOOQ-manual/src/main/resources/org/jooq/web/grammar-3.12.txt
@@ -867,7 +867,7 @@ dataType =
 | 'CHARACTER' [ '(' unsignedInteger ')' [ 'BYTE' | 'CHAR' ] ] [ 'COLLATE' collationName ]
 | 'CLOB' [ '(' unsignedInteger ')' ] [ 'COLLATE' collationName ]
 | 'DATE'
-| 'DECIMAL' [ '(' ( '*' | unsignedInteger ) [ ',' unsignedInteger ] ')' ]
+| 'DECIMAL' [ '(' ( '*' | unsignedInteger ) [ ',' signedInteger ] ')' ]
 | 'DOUBLE' [ 'PRECISION' ] [ '(' unsignedInteger [ ',' unsignedInteger ] ')' ]
 | 'ENUM' '(' stringLiteral [ ',' stringLiteral ] ')' [ 'COLLATE' collationName ]
 | 'FLOAT' [ '(' unsignedInteger [ ',' unsignedInteger ] ')' ]
@@ -883,8 +883,8 @@ dataType =
 | 'MEDIUMTEXT' [ 'COLLATE' collationName ]
 | 'NCHAR' [ '(' unsignedInteger ')' ] [ 'COLLATE' collationName ]
 | 'NCLOB' [ 'COLLATE' collationName ]
-| 'NUMBER' [ '(' ( '*' | unsignedInteger ) [ ',' unsignedInteger ] ')' ]
-| 'NUMERIC' [ '(' ( '*' | unsignedInteger ) [ ',' unsignedInteger ] ')' ]
+| 'NUMBER' [ '(' ( '*' | unsignedInteger ) [ ',' signedInteger ] ')' ]
+| 'NUMERIC' [ '(' ( '*' | unsignedInteger ) [ ',' signedInteger ] ')' ]
 | 'NVARCHAR' [ '(' unsignedInteger ')' ] [ 'COLLATE' collationName ]
 | 'OTHER'
 | 'REAL' [ '(' unsignedInteger [ ',' unsignedInteger ] ')' ]
diff --git a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
index 68ec1b5bce..11f5009ae3 100644
--- a/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
+++ b/jOOQ/src/main/java/org/jooq/impl/ParserImpl.java
@@ -7677,7 +7677,7 @@ final class ParserImpl implements Parser {
             int precision = parseIf(ctx, '*') ? 38 : (int) (long) parseUnsignedInteger(ctx);
 
             if (parseIf(ctx, ','))
-                result = result.precision(precision, (int) (long) parseUnsignedInteger(ctx));
+                result = result.precision(precision, (int) (long) parseSignedInteger(ctx));
             else
                 result = result.precision(precision);