diff --git a/lib/SQL/Translator/Producer/PostgreSQL.pm b/lib/SQL/Translator/Producer/PostgreSQL.pm
index 455f745df..5f7f55104 100644
--- a/lib/SQL/Translator/Producer/PostgreSQL.pm
+++ b/lib/SQL/Translator/Producer/PostgreSQL.pm
@@ -602,6 +602,11 @@ sub create_constraint
         push @fks, "$def";
     }
 
+    # This seemed preferable to doing it in every junction of that if
+    if ($c->deferrable and $c->type ne FOREIGN_KEY) {
+        $constraint_defs[-1] .= ' DEFERRABLE';
+    }
+
     return \@constraint_defs, \@fks;
 }
 
diff --git a/lib/SQL/Translator/Schema/Constraint.pm b/lib/SQL/Translator/Schema/Constraint.pm
index 7742bf777..9dd7da41f 100644
--- a/lib/SQL/Translator/Schema/Constraint.pm
+++ b/lib/SQL/Translator/Schema/Constraint.pm
@@ -56,6 +56,7 @@ Object constructor.
       match_type       => 'full',        # how to match
       on_delete        => 'cascade',     # what to do on deletes
       on_update        => '',            # what to do on updates
+      deferrable       => 0,             # whether to set DEFERRABLE, if supported by the database
   );
 
 =cut
@@ -78,9 +79,10 @@ around BUILDARGS => sub {
 
 =head2 deferrable
 
-Get or set whether the constraint is deferrable.  If not defined,
-then returns "1."  The argument is evaluated by Perl for True or
-False, so the following are equivalent:
+Get or set whether the constraint is deferrable. The default is based on the
+constraint type. Foreign keys are deferrable by default, for backward
+compatibility; all other types are not. The argument is evaluated by Perl for
+True or False, so the following are equivalent:
 
   $deferrable = $field->deferrable(0);
   $deferrable = $field->deferrable('');
@@ -91,7 +93,10 @@ False, so the following are equivalent:
 has deferrable => (
     is => 'rw',
     coerce => quote_sub(q{ $_[0] ? 1 : 0 }),
-    default => quote_sub(q{ 1 }),
+    lazy => 1,
+    default => sub {
+        $_[0]->type eq FOREIGN_KEY
+    },
 );
 
 =head2 expression
diff --git a/lib/Test/SQL/Translator.pm b/lib/Test/SQL/Translator.pm
index 0181156a1..bbd31544d 100644
--- a/lib/Test/SQL/Translator.pm
+++ b/lib/Test/SQL/Translator.pm
@@ -49,7 +49,7 @@ my %ATTRIBUTES = (
     constraint => {
         name             => '',
         type             => '',
-        deferrable       => 1,
+        deferrable       => 0,
         expression       => '',
         is_valid         => 1,
         fields           => [],
@@ -135,6 +135,11 @@ sub default_attribs {
         $hashref->{ $attr } = $ATTRIBUTES{ $object_type }{ $attr }
     }
 
+    # Special case
+    if ($object_type eq 'constraint' and $hashref->{type} eq FOREIGN_KEY) {
+        $hashref->{deferrable} = 1;
+    }
+
     return $hashref;
 }
 
diff --git a/t/17sqlfxml-producer.t b/t/17sqlfxml-producer.t
index 7989e35d4..f559a0264 100644
--- a/t/17sqlfxml-producer.t
+++ b/t/17sqlfxml-producer.t
@@ -87,10 +87,10 @@ $ans = <<EOXML;
         </index>
       </indices>
       <constraints>
-        <constraint name="" type="PRIMARY KEY" fields="id" reference_table="" reference_fields="" on_delete="" on_update="" match_type="" expression="" options="" deferrable="1">
+        <constraint name="" type="PRIMARY KEY" fields="id" reference_table="" reference_fields="" on_delete="" on_update="" match_type="" expression="" options="" deferrable="0">
           <extra />
         </constraint>
-        <constraint name="" type="UNIQUE" fields="email" reference_table="" reference_fields="" on_delete="" on_update="" match_type="" expression="" options="" deferrable="1">
+        <constraint name="" type="UNIQUE" fields="email" reference_table="" reference_fields="" on_delete="" on_update="" match_type="" expression="" options="" deferrable="0">
           <extra />
         </constraint>
       </constraints>
diff --git a/t/23json.t b/t/23json.t
index 7ed847ea3..416a7c608 100644
--- a/t/23json.t
+++ b/t/23json.t
@@ -24,7 +24,7 @@ my $json = from_json(<<JSON);
          "person" : {
             "constraints" : [
                {
-                  "deferrable" : 1,
+                  "deferrable" : 0,
                   "expression" : "",
                   "fields" : [
                      "person_id"
@@ -39,7 +39,7 @@ my $json = from_json(<<JSON);
                   "type" : "PRIMARY KEY"
                },
                {
-                  "deferrable" : 1,
+                  "deferrable" : 0,
                   "expression" : "",
                   "fields" : [
                      "name"
@@ -142,7 +142,7 @@ my $json = from_json(<<JSON);
          "pet" : {
             "constraints" : [
                {
-                  "deferrable" : 1,
+                  "deferrable" : 0,
                   "expression" : "",
                   "fields" : [],
                   "match_type" : "",
@@ -155,7 +155,7 @@ my $json = from_json(<<JSON);
                   "type" : "CHECK"
                },
                {
-                  "deferrable" : 1,
+                  "deferrable" : 0,
                   "expression" : "",
                   "fields" : [
                      "pet_id",
diff --git a/t/24yaml.t b/t/24yaml.t
index 8c6d1cf05..19ab9b371 100644
--- a/t/24yaml.t
+++ b/t/24yaml.t
@@ -21,7 +21,7 @@ schema:
   tables:
     person:
       constraints:
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - person_id
@@ -33,7 +33,7 @@ schema:
           reference_fields: []
           reference_table: ''
           type: PRIMARY KEY
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - name
@@ -117,7 +117,7 @@ schema:
       order: 1
     pet:
       constraints:
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields: []
           match_type: ''
@@ -128,7 +128,7 @@ schema:
           reference_fields: []
           reference_table: ''
           type: CHECK
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - pet_id
diff --git a/t/30sqlt-new-diff-pgsql.t b/t/30sqlt-new-diff-pgsql.t
index 5bc782038..07e51ed8d 100644
--- a/t/30sqlt-new-diff-pgsql.t
+++ b/t/30sqlt-new-diff-pgsql.t
@@ -90,7 +90,7 @@ ALTER TABLE "person" ADD CONSTRAINT "unique_name" UNIQUE ("name");
 
 ALTER TABLE "person" ADD CONSTRAINT "UC_person_id" UNIQUE ("person_id");
 
-ALTER TABLE "person" ADD CONSTRAINT "UC_age_name" UNIQUE ("age", "name");
+ALTER TABLE "person" ADD CONSTRAINT "UC_age_name" UNIQUE ("age", "name") DEFERRABLE;
 
 DROP TABLE "deleted" CASCADE;
 
@@ -143,7 +143,7 @@ ALTER TABLE person RENAME COLUMN description TO physical_description;
 
 ALTER TABLE person ADD CONSTRAINT UC_person_id UNIQUE (person_id);
 
-ALTER TABLE person ADD CONSTRAINT UC_age_name UNIQUE (age, name);
+ALTER TABLE person ADD CONSTRAINT UC_age_name UNIQUE (age, name) DEFERRABLE;
 
 DROP TABLE deleted CASCADE;
 
diff --git a/t/39-filter-globals.t b/t/39-filter-globals.t
index cd79f9ef8..d5ef796c1 100644
--- a/t/39-filter-globals.t
+++ b/t/39-filter-globals.t
@@ -90,7 +90,7 @@ is_deeply ($struct, {
       Person => {
         constraints => [
           {
-            deferrable => 1,
+            deferrable => 0,
             expression => "",
             fields => [
               "modified"
diff --git a/t/47postgres-producer.t b/t/47postgres-producer.t
index 9c50db736..08a043bc6 100644
--- a/t/47postgres-producer.t
+++ b/t/47postgres-producer.t
@@ -22,6 +22,16 @@ BEGIN {
 use Test::Differences;
 use SQL::Translator;
 
+# normalised-space-is, i.e. are these the same after normalising whitespace?
+sub ns_is {
+    my ($first, $second) = (shift, shift);
+    $first =~ s/\s+/ /g;
+    $second =~ s/\s+/ /g;
+
+    # avoid prototype
+    &is( $first, $second, @_ );
+}
+
 my $PRODUCER = \&SQL::Translator::Producer::PostgreSQL::create_field;
 
 {
@@ -146,32 +156,39 @@ for my $name ( 'foo', undef ) {
         type   => 'FOREIGN_KEY',
         reference_table => $table2,
         reference_fields => [qw(myfield_2)],
+        deferrable => 0,
     );
 
-    my  ($fk_constraint_def_ref, $fk_constraint_fk_ref ) = SQL::Translator::Producer::PostgreSQL::create_constraint($fk_constraint);
+    for my $constraint ($fk_constraint, $fk_constraint_2) {
+        my  ($fk_constraint_def_ref, $fk_constraint_fk_ref ) = SQL::Translator::Producer::PostgreSQL::create_constraint($constraint);
 
-    ok(@{$fk_constraint_def_ref} == 0 && @{$fk_constraint_fk_ref} == 1,  'precheck of create_Foreign Key constraint');
+        ok(@{$fk_constraint_def_ref} == 0 && @{$fk_constraint_fk_ref} == 1,  'precheck of create_Foreign Key constraint');
 
-    if ( $name ) {
-        is($fk_constraint_fk_ref->[0], "ALTER TABLE mytable ADD CONSTRAINT $name FOREIGN KEY (myfield)
-  REFERENCES mytable2 (myfield_2) DEFERRABLE", 'Create Foreign Key Constraint works');
+        my $deferrable = $constraint->deferrable ? ' DEFERRABLE' : '';
 
-        # ToDo: may we should check if the constraint name was valid, or if next
-        #       unused_name created has choosen a different one
-        my $alter_fk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($fk_constraint);
-        is($alter_fk_constraint, "ALTER TABLE mytable DROP CONSTRAINT $name", 'Alter drop Foreign Key constraint works');
-    }
-    else {
-        is($fk_constraint_fk_ref->[0], 'ALTER TABLE mytable ADD FOREIGN KEY (myfield)
-  REFERENCES mytable2 (myfield_2) DEFERRABLE', 'Create un-named Foreign Key Constraint works');
+        if ( $name ) {
 
-        my $alter_fk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($fk_constraint);
-        is($alter_fk_constraint, 'ALTER TABLE mytable DROP CONSTRAINT mytable_myfield_fkey', 'Alter drop un-named Foreign Key constraint works');
+            ns_is($fk_constraint_fk_ref->[0], "ALTER TABLE mytable ADD CONSTRAINT $name FOREIGN KEY (myfield)
+      REFERENCES mytable2 (myfield_2)$deferrable", 'Create Foreign Key Constraint works');
+
+            # ToDo: may we should check if the constraint name was valid, or if next
+            #       unused_name created has choosen a different one
+            my $alter_fk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($constraint);
+            is($alter_fk_constraint, "ALTER TABLE mytable DROP CONSTRAINT $name", 'Alter drop Foreign Key constraint works');
+        }
+        else {
+            ns_is($fk_constraint_fk_ref->[0], "ALTER TABLE mytable ADD FOREIGN KEY (myfield)
+      REFERENCES mytable2 (myfield_2)$deferrable", 'Create un-named Foreign Key Constraint works');
+
+            my $alter_fk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($constraint);
+            is($alter_fk_constraint, 'ALTER TABLE mytable DROP CONSTRAINT mytable_myfield_fkey', 'Alter drop un-named Foreign Key constraint works');
+        }
     }
 }
 
 # check named, and unnamed primary keys
 for my $name ( 'foo', undef ) {
+    # PK defaults to deferrable => 0
     my $pk_constraint = SQL::Translator::Schema::Constraint->new(
         table => $table,
         name   => $name,
@@ -183,23 +200,27 @@ for my $name ( 'foo', undef ) {
         name   => $name,
         fields => [qw(myfield)],
         type   => 'PRIMARY_KEY',
+        deferrable => 1,
     );
 
-    my  ($pk_constraint_def_ref, $pk_constraint_pk_ref ) = SQL::Translator::Producer::PostgreSQL::create_constraint($pk_constraint);
+    for my $pk ($pk_constraint, $pk_constraint_2) {
+        my  ($pk_constraint_def_ref, $pk_constraint_pk_ref ) = SQL::Translator::Producer::PostgreSQL::create_constraint($pk);
 
-    if ( $name ) {
-        is($pk_constraint_def_ref->[0], "CONSTRAINT $name PRIMARY KEY (myfield)", 'Create Primary Key Constraint works');
+        my $deferrable = $pk->deferrable ? ' DEFERRABLE' : '';
+        if ( $name ) {
+            is($pk_constraint_def_ref->[0], "CONSTRAINT $name PRIMARY KEY (myfield)$deferrable", 'Create Primary Key Constraint works');
 
-        # ToDo: may we should check if the constraint name was valid, or if next
-        #       unused_name created has choosen a different one
-        my $alter_pk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($pk_constraint);
-        is($alter_pk_constraint, "ALTER TABLE mytable DROP CONSTRAINT $name", 'Alter drop Primary Key constraint works');
-    }
-    else {
-        is($pk_constraint_def_ref->[0], 'PRIMARY KEY (myfield)', 'Create un-named Primary Key Constraint works');
+            # ToDo: may we should check if the constraint name was valid, or if next
+            #       unused_name created has choosen a different one
+            my $alter_pk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($pk);
+            is($alter_pk_constraint, "ALTER TABLE mytable DROP CONSTRAINT $name", 'Alter drop Primary Key constraint works');
+        }
+        else {
+            is($pk_constraint_def_ref->[0], "PRIMARY KEY (myfield)$deferrable", 'Create un-named Primary Key Constraint works');
 
-        my $alter_pk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($pk_constraint);
-        is($alter_pk_constraint, 'ALTER TABLE mytable DROP CONSTRAINT mytable_pkey', 'Alter drop un-named Foreign Key constraint works');
+            my $alter_pk_constraint = SQL::Translator::Producer::PostgreSQL::alter_drop_constraint($pk);
+            is($alter_pk_constraint, 'ALTER TABLE mytable DROP CONSTRAINT mytable_pkey', 'Alter drop un-named Foreign Key constraint works');
+        }
     }
 }
 
diff --git a/t/data/diff/pgsql/create1.yml b/t/data/diff/pgsql/create1.yml
index d31314641..c77e3743c 100644
--- a/t/data/diff/pgsql/create1.yml
+++ b/t/data/diff/pgsql/create1.yml
@@ -45,7 +45,7 @@ schema:
             - person_id
           reference_table: person
           type: FOREIGN KEY
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - position
@@ -111,7 +111,7 @@ schema:
       order: 4
     person:
       constraints:
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - person_id
diff --git a/t/data/diff/pgsql/create2.yml b/t/data/diff/pgsql/create2.yml
index b58fdee8d..2a27df649 100644
--- a/t/data/diff/pgsql/create2.yml
+++ b/t/data/diff/pgsql/create2.yml
@@ -35,7 +35,7 @@ schema:
             - person_id
           reference_table: person
           type: FOREIGN KEY
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - employee_id
@@ -96,7 +96,7 @@ schema:
       order: 4
     person:
       constraints:
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - person_id
@@ -108,7 +108,7 @@ schema:
           reference_fields: []
           reference_table: ''
           type: PRIMARY KEY
-        - deferrable: 1
+        - deferrable: 0
           expression: ''
           fields:
             - person_id
diff --git a/t/data/template/testresult_basic.txt b/t/data/template/testresult_basic.txt
index 8a7d2e95c..cc1f0f2c8 100644
--- a/t/data/template/testresult_basic.txt
+++ b/t/data/template/testresult_basic.txt
@@ -152,7 +152,7 @@ Constraints
         match_type:       
         reference_fields: 
         reference_table:  
-        deferrable:       1
+        deferrable:       0
         on_delete:        
         on_update:        
         options:          
@@ -165,7 +165,7 @@ Constraints
         match_type:       
         reference_fields: 
         reference_table:  
-        deferrable:       1
+        deferrable:       0
         on_delete:        
         on_update:        
         options:          
@@ -178,7 +178,7 @@ Constraints
         match_type:       
         reference_fields: 
         reference_table:  
-        deferrable:       1
+        deferrable:       0
         on_delete:        
         on_update:        
         options:          
@@ -240,7 +240,7 @@ Constraints
         match_type:       
         reference_fields: 
         reference_table:  
-        deferrable:       1
+        deferrable:       0
         on_delete:        
         on_update:        
         options:          
diff --git a/t/data/xml/schema.xml b/t/data/xml/schema.xml
index 048d8577f..295891907 100644
--- a/t/data/xml/schema.xml
+++ b/t/data/xml/schema.xml
@@ -49,12 +49,12 @@ Created on Fri Aug 15 15:08:18 2003
 
         <constraints>
           <constraint name="" type="PRIMARY KEY" fields="id"
-              reference_table="" options="" deferrable="1" match_type=""
+              reference_table="" options="" deferrable="0" match_type=""
               expression="" on_update="" on_delete="">
               <extra foo="bar" hello="world" bar="baz" />
           </constraint>
-          <constraint name="emailuniqueindex" type="UNIQUE" fields="email" />
-          <constraint name="very_long_index_name_on_title_field_which_should_be_truncated_for_various_rdbms" type="UNIQUE" fields="title" />
+          <constraint name="emailuniqueindex" type="UNIQUE" fields="email" deferrable="0" />
+          <constraint name="very_long_index_name_on_title_field_which_should_be_truncated_for_various_rdbms" type="UNIQUE" fields="title" deferrable="0" />
           <constraint name="" type="FOREIGN KEY" fields="another_id"
               reference_table="Another" options="" deferrable="1" match_type=""
               expression="" on_update="" on_delete="">
@@ -81,7 +81,7 @@ Created on Fri Aug 15 15:08:18 2003
 
         <constraints>
           <constraint name="" type="PRIMARY KEY" fields="id"
-              reference_table="" options="" deferrable="1" match_type=""
+              reference_table="" options="" deferrable="0" match_type=""
               expression="" on_update="" on_delete="">
           </constraint>
         </constraints>